♪♪ -I'm Darius Arya, an archaeologist going in search of the ancient world in three of the most exciting cities on Earth -- Cairo, the gateway to ancient Egypt... Istanbul, the crossroads between Europe and Asia... and, now, Athens, the birthplace of democracy.

♪♪ Today Greater Athens is home to almost 4 million people.

The city has exploded with new life in the past century.

Here's a place that ancient monuments and sites sit side by side with modern architecture and urban renewal.

It's an intoxicating mixture of ancient and contemporary all together.

I'll be investigating this city's hidden sites to find out how the ancient Athenians created an idea that has endured for over two-and-a-half-thousand years -- democracy.

And I'll use virtual reality... Whoa!

...to explore this amazing place in a whole new way.

What a view.

Athens is a city with layer after layer of history and mythology.

The ancients called this place the City of the Gods.

Welcome to invisible Athens.

♪♪ ♪♪ ♪♪ ♪♪ -The Acropolis, a sacred hill in the center of Athens.

♪♪ 5,000 years ago, its cliffs offered protection to Bronze Age settlers.

And in the centuries that followed, the city grew up around it.

Today, it is famous for a series of events that started here in 510 B.C.

when the people of Athens overthrew a tyrant besieged on this hillside, and did something extraordinary.

They started to create the world's first democracy.

In the golden era that followed, this remarkable society built the beautiful monuments that still stand here today.

♪♪ I'm walking through the propylaea, the monumental entry hall that leads you forward into the Acropolis.

And it's designed to be theatrical and leave you with the sense of expectation of something greater that lies ahead, that brings you forward to this exact spot that gives you the most perfect view of one of the most famous buildings in the world.

♪♪ The Parthenon was built to honor the goddess Athena.

It's been at the heart of what it means to be Athenian for over two-and-a-half-thousand years.

♪♪ Its orderly columns and perfect symmetry became the classical blueprint for architecture that shapes the world to this day.

♪♪ And right next door is one of the most intriguing buildings in the world.

It might be small, but it's by no means insignificant.

And we're going to find out why it's one of the most important buildings of ancient Athens.

The Parthenon is famous for its symmetry, but across the way, the Erechtheion, it's contemporary, but it looks totally different.

♪♪ This is a structure known for housing the votive statue of Athena, and many other shrines, but when we look at the architecture it's like a mishmash of design.

Even the ancient commentators were confused.

Now, if we look at the individual architectural components, they are beautiful and refined as the Parthenon, but overall, for its design, it just doesn't make any sense.

Why did they build it in this way?

♪♪ Our 3D scanners are gonna try to make sense of this quirky little temple.

The team is led by architect Matt Shaw.

Looking over at the Parthenon, that's one kind of structure, and then this, it's like totally different.

-Yeah.

Classical clarity, over there, and then this confusing little structure without really a clear front or a clear entranceway.

What were all of these different spaces inside?

That's what we're hoping to try and understand with our scans.

-So, you've got total access.

You're outside.

You're inside.

You've got the drones.

What are the real challenges, then, in creating these models today?

-The building is the challenge for us, really, and we've got to use technology to try and unravel it.

-To reveal more about the Erechtheion setting, Matt and his team are also going to create a 3D model of the whole Acropolis.

Using thousands of aero photographs and a digital process called photogrammetry, they'll be trying to reveal why the Athenians designed the Erechtheion in this way.

While the scanning team goes to work, I'm going to have a closer look.

The Erechtheion gets its name from Erechtheus, a mythical king of Athens.

He is said to have been killed here by a thunderbolt thrown by Zeus, the king of the gods, a myth that has been cleverly incorporated in the building itself.

This might look like damage to the roof, but in fact, its purposely left open in this spot to remember the point at which Zeus throws the lightning bolt and kills the king Erechtheus.

The temple also tells the story of how the city itself was named, and according to one version of the myth, it happened right here when Poseidon, the god of the sea, and Athena, the goddess of wisdom, took part in a duel to become the patron god of the city below.

♪♪ Each god had to offer something to the city.

Poseidon began.

He struck the earth right down below here, and out burst a spring of saltwater.

In response to Poseidon's saltwater spring, Athena made grow on this spot an olive tree, and the kind decided that Athena won the competition because the olive tree was much more useful.

And she became the patron deity of Athens.

Today, an olive tree still grows on the site where the city was named.

♪♪ But the myths don't end there.

Jutting out from another site of the Erechtheion is a strange porch, which our scan team has been given special access to investigate.

It is held up by columns in the form of maidens.

Known as the caryatid, they are guardians of yet more sacred royal ground.

And what they're doing is standing as an offering to mourn the loss of the mythical king Cecrops, who's located in his grave down below.

This is an important feature of the Erechtheion, reminding the Athenians that these women are mourning perpetually the loss of the mythic king.

♪♪ For the ancient Athenians, these buildings were the sacred heart of their city, created for a belief system that lasted thousands of years and is now lost in time.

But the political heart of their city lies elsewhere...

Sitting just below the Acropolis is a hill called the Pnyx.

Athenian citizens assembled on this hillside to hear speeches and vote directly on every issue.

If anywhere could lay claim to being the world's first democratic meeting place, then this is it.

♪♪ But this wasn't democracy as we know it.

Only Athenian men were classed as citizens, and there were no votes for women, nor Athens' army of slaves.

And that makes it difficult now for many of us to recognize this as a democracy at all.

So when we look at Athenian democracy in our own terms, we have problems with it, but so too would the Athenians look at our modern democratic states and say, "What kind of democracy is that?

Every individual citizen doesn't cast a vote for every decision."

This is what Athenian democracy was all about.

This is where it started, and it was something unique.

So many of the secrets of ancient Athens are hidden beneath the surface of the modern city.

Our scan team had been hard at work investigating them.

Hey, Matt.

-Hello.

How are you?

-All right.

I'm looking forward to seeing what you've come up with here.

How you doin', man?

And now, they're ready to show me the first images of the Acropolis.

-I mean, thousands of individual images and then a good chunk of computing power and we get this quite amazing 3D model, and obviously dominated by this perfect piece of classical Greek architecture.

-[ Chuckles ] Yeah.

-But obviously we are a little more interested in its strange sibling over here, over on the... -Off to the side, there.

-Off to the side.

-It seems like it's about to tip off the side of the Acropolis there, just pushed off to the side.

Look at that.

Let's take this model apart a little bit.

We're gonna take the Erechtheion away.

The first thing to say about this site is that it's not level.

We've got a change in elevation of about 3 1/2 meters as we go from the south to the north side of the temple.

Traditionally, if you're building a building, you'd start leveling up that side, right?

-Yeah.

-But we can't do that here, because this is sacred ground, right?

-So you're stuck with that.

You're left to deal with that.

-Yeah.

So, the first one of them is this strange hole.

-For them, it was god reaching out and touching this particular monument or space, and that became instantly sacred.

Like this.

You really see the connection.

It becomes very obvious.

-You can see this hole in the ceiling that is directly above.

-Oh, yeah.

But, wow.

I mean, like, that... [chuckles] no one's ever seen, which is incredible.

-This isn't the only moment of very intentional precision that's going on on the porch here as well.

I mean, if we just look at one of these columns then... -Wow.

Look at that.

-That level of perfection carries on to these details, which humans can never see, because this building isn't just designed for humans to see, right?

This is for the gods.

-Yeah.

-There's something stopping them extending the building.

If I just click here we get Athena's olive tree.

-Ah, yes.

-This is another constraint for the building program here, right?

You can't cut down Athena's olive tree.

I mean, we do this nowadays, right?

We have tree-preservation orders, right?

I mean, you are not cutting that tree down to build your temple.

And then there's a third real constraint on the site, another mythical moment, the burial ground of Cecrops, right?

-With the caryatid.

-Yeah.

-By having that space sort of bump out, you're clueing in, you know, the pilgrim that's coming here that this is yet another sacred space.

-We've got the burial mound of Cecrops.

We've got a hole for a thunderbolt.

It's a hell of a brief, right?

-A spot of ground touched by the gods.

An olive tree created by Athena.

And the tomb of Athens' founding king.

Thousands of years ago, parents would bring their kids here.

They'd be able to tell those stories as they went around this space that they were privileged enough to go inside and to see those very shrines with their own eyes.

And it's like a story book that just enfolds as you make your way around it.

The Erechtheion, it's kind of a mess.

I mean, it's these disparate parts, it doesn't line up, but you've shown with the scans it can't be symmetrical, it can't be as obvious as the Parthenon across the way.

This is a much more complex structure, and you've teased out so many of these details.

♪♪ ♪♪ [ Yelling in native language ] ♪♪ Today, modern Athens is a vivid and colorful city with a strong connection to the sea.

It's the bustling capital of a democracy struggling to keep up with its neighbors.

[ Indistinct yelling ] And in the time of the first democracy, Athens also had to fight for its place in the world.

♪♪ In 490 B.C., Athens was a Greek city-state surrounded by rivals -- Aegina, Corinth, and the militaristic Sparta.

The greatest threat of all lay to the East, where the Persian empire was growing in power and ambition.

But Athens had one great advantage over many of its rivals.

The entire peninsula of Attica was under its control, and 50 miles to the south of the city lay extensive seams of precious silver buried deep in the hillsides of an area called Laurium.

♪♪ In the 5th century B.C., this was an industrial landscape, given over to silver mining, a lucrative business run for the benefit of Athens and its citizens, but carried out by the city's army of slaves.

To find out more about this dark underbelly of Athens, I'm gonna go inside one of the ancient mines.

-Mind your head.

-My guide is archeologist/professor Andreas Kapetanios.

-Whoa.

It's pretty low.

This is... oof.

-It's not a very big entrance just getting inside here.

-It's just the beginning.

We have to go through that gully over there.

You see?

-Looks pretty tight.

-It is.

Narrow and low.

-[ Groans ] It is not built for my size, looks like.

I feel like a giant going through a little pipe.

-Down here we notice this, deep cleat marks.

There are cleat marks all around.

-Yeah.

-You see, this is a kind of step.

-It's getting pretty gnarly right here.

-We have to crawl from here.

-Okay.

It's like doing limbo on your stomach.

[ Groans ] -[ Chuckling ] Yeah.

-If I get stuck, you're gonna help me, right?

-Right.

-You're not gonna leave me behind, right?

[ Chuckles ] This is a place where you really want to be an expert.

I have no idea where I'm going.

I need to stick with Andreas.

-So, we move that way.

-Okay.

-Are you coming?

-Yeah.

I'm on my way.

The rare access I've been granted to these tunnels really brings home to me the plight of the people who hacked them out by hand two-and-a-half-thousand years ago.

-This was leveled down by tens of thousands of slaves.

Slaves were captures in wars or they were bought in markets.

Slaves were very valuable.

That's why they were valuable tools.

-Only by scanning will the scale and complexity of this grim labyrinth of tunnels and galleries become clear, but it's going to be the hardest challenge Matt and his team have faced yet.

-I do think we got a while in here.

I think we've got about six hours, probably.

-So you guys will be here all night.

-Yeah.

I mean, it's teamwork, right?

One of us has got to creep through these holes and the other one has got to pass the equipment, and then we've got to creep again and pass again, creep again and pass again.

-Crawling around through here I'm getting a sense that this is an awful existence.

You don't want to be a slave, and this is pretty much the bottom of where a slave would be.

Although the people that worked here were anonymous, they're part of a long, complicated organization in existence.

To make democracy in Athens work, this is part of it.

This is a very dirty part of it.

-And through here we're getting in a wider space.

-Is there anything left of the good stuff, let's say?

-No, nothing is left of the good stuff, but I have something in my pocket.

I can show you a piece.

You need four tons of this to produce two kilos of silver.

Two kilos.

Like five pounds.

These are the silicon valleys of classical Athens.

-[ Chuckles ] ♪♪ Our scans show the interior of the mine in extraordinary detail, and reveal the labyrinth of tunnels to be hundreds of yards long.

♪♪ Cut by hand as miners and slaves followed a thin seam of silver ore into the hillside.

♪♪ Above the ground, the scan team also captures the mine's processing plants.

Here, the ore would've been washed then ground into tiny pebbles before finally being heated in a furnace nearby to coax out the precious silver.

This is just one of at least 30 silver mines hidden under the hillsides of Laurium.

And in the 480's B.C., they provided Athens with a bounty of nearly three tons of silver, an unexpected boost to Athens' new democracy.

♪♪ [ Car horn honking ] ♪♪ I've come to Athens' harbor district, called Piraeus, on the trail of that silver windfall.

It created a huge debate here among the citizens.

In 483 B.C., a heroic general and leading politician called Themistocles put forward a case that the money should be spent on a fleet of war ships.

But others wanted to divide up the windfall and give all the citizens an equal share in hard cash.

And it was settled with a vote.

The people made the extraordinary decision to back Themistocles.

Instead of spending the windfall, they decided to invest the silver and build a fleet.

♪♪ Over 100 new war ships, like this, were commissioned, known as triremes because of their three rows of ores.

At 40-yards long, they were light and fast.

And fitted with bronze battering rams, they were formidable weapons of war.

♪♪ And here on the waterfront we can peel back the layers of history to show the importance of the Athenian fleet for several centuries.

The scan team is already investigating.

-How's it goin'?

So, how are the challenges here in this particular location?

-We have a tricky one, okay?

So, we know something is hiding away in the basement of his structure over here, and then we know those structures actually start in the basement, but they came some way out underneath... -Right, even underneath us.

-Exactly.

...And out into the water.

Now, scanning in the water is a wee bit tricky... -Yeah.

-... so we're taking to the air for this one.

-Okay.

♪♪ While the scan team gets to work, I'm going to access a remarkable site with marine archaeologist Dr. Bjorn Loven.

We are now walking into the very space of the ship sheds.

-It's right underneath this modern apartment block.

Oh, wow!

Yeah.

From outside I got no sense of it, but here it is.

I mean, this is an incredible archaeological site.

Totally hidden away!

-Yeah, welcome to one of the secret sites of Greece.

-Totally invisible.

Everyone's going by.

You don't know what's underneath here in this basement.

Dry-dock ship sheds like this one seem like a simple enough idea, but they were vital to the success of Athens' naval fleet.

-If you stand on this column base... -Okay.

Yeah.

-...I'll walk through this here... -Ah, okay.

-...all the way over to the other column.

So, between the two of us, we have one ship shed.

-My God.

-So in this space there would have been a trireme.

-And you'd be able to slip in a war ship, right here between us.

-Yes.

If you join me over here... -Yeah.

-...next to the ramp, there's a working space where the people pulled the war ships in and out of the ship sheds.

-You're doing that labor.

You're actively giving...

Hundreds of guys I imagine are pulling this.

-Yeah.

I mean, we know from a source from the fifth century B.C.

that it took 140 men to pull a trireme out of the sea.

-And then you multiply that by the number of sheds, by the number of ships.

It starts to become an enormous neighborhood, right?

-It is a major operation.

I mean, the ship sheds are all important because it maintains and preserves the war ships and makes sure that it is operational when it's sent out on missions.

The drier and the more well-maintained your ship is, the faster it is in battle.

♪♪ -Our scans show how the modern apartments are built right on top of the ancient ship sheds.

♪♪ Using data gathered from our drone, we've been able to map remains, now underwater, that reveal how the ship sheds extend into the harbor.

And our graphic shows how they once stood all around this cove.

In 480 B.C., the Athenian navy was 200-ships strong, just as Athens was about to face a mortal threat from the most powerful empire in the ancient world.

♪♪ A little down the road from where I was exploring the ship sheds is Athens' modern port, and this is where a decisive sequence of events began.

A massive army of at least 200,000 Persians was on its way to invade Athens and crush its democracy.

♪♪ With the entire population at risk, Athenians had to decide whether to stay and fight in the city or to retreat by sea.

♪♪ Themistocles realized it would've been disastrous to wage a land battle against a much more massive Persian army, so the extraordinary decision was made to evacuate the city of Athens and all the lands of Attica.

♪♪ Women and children were taken to safety, and every male citizen of military age took his place on a trireme and prepared to face the Persians at sea.

♪♪ The Athenians withdrew their fleet just a short distance across the water from the city, into a secluded bay where they could plan their next move.

♪♪ Here they were joined by allies from across Greece, and in late September, 480 B.C., they prepared to make a last stand.

♪♪ The battle that followed, the Battle of Salamis, saw not just Athens' future, but the future of Western civilization, hang in the balance.

Because if Athens fell and democracy was extinguished, it may never have caught flame again.

Until recently, barely any remains dating from this moment were thought to have survived.

But in 2017, Professor Yannas Lolos discovered evidence that helps explain what this little bay might have been like at the time.

-On the eve of the sea battle of Salamis, the united Greek fleet, with over 300 triple-decker war ships, was stationed in this bay.

So we have documented the existence of a harbor.

It's a fortified harbor.

It would have been a long wall with a round tower at its end.

-Can you help me reconstruct what it would've been like?

-The Athenians could see from the heights surrounding this bay the city in flames, including the Acropolis.

That night was the zero hour of Greek history.

♪♪ -Using the new research, our scan team has managed to fix the coordinates of the archaeological remains here at Salamis.

Our graphic model of the harbor wall and its defensive tower shows how it extended 160 yards into the bay.

This is where over 300 Greek trireme war ships gathered to take on a Persian force three times that size.

One source says that Themistocles lured the Persians into the narrow straits beyond the bay, where superior numbers counted for nothing.

The Greek triremes pounced and rammed into the Persians, smashing their fleet apart.

The Greeks lost 40 ships that day, but the Persians lost 300.

It was a stunning victory for Athens, one that allowed the world's first democracy to survive.

♪♪ But victory came at a high price.

♪♪ The people returned to a city that had been razed to the ground.

♪♪ Over 30 years, the Athenians lived amongst the ruins.

They didn't rebuild the city for all that time, because they wanted that destruction to serve as a reminder of what had happened to them.

Actually, they did build one thing.

I'm looking for it right now.

It's right around the corner.

This is the road... ♪♪ ♪♪ It's supposed to be right over here, kind of to the left of the bathroom.

And there's supposed to be a staircase going down.

Today this parking garage is right in the heart of a sprawling metropolis, but it was once the city limits of ancient Athens.

♪♪ Ho-ho!

Look at this.

We made it.

I mean, it's not every day you walk into an underground parking lot and find something like this.

This is a circuit of wall that's over 2,500 years old.

It's been constructed thanks to Themistocles, and it's about 80-feet long or so and it's still in place.

You can count, what, about five courses here of stone.

Think about the effort, the manpower that's employed to construct this.

♪♪ Just as every Athenian citizen had been expected to row in the battle of Salamis, now they were expected, in the city of Athens, to build walls, these walls, and they put it together, encircling the entire city in record time.

♪♪ Our scans reveal that these walls concealed inside the parking garage were just the beginning of a series of building projects that would transform Athens and allow its citizens and their way of life a chance to thrive.

♪♪ First of all, they enclosed what remained of the city, then, six miles away, they fortified the vital port of Piraeus.

♪♪ And then, most impressively of all, they linked the two with a fortified corridor that ran all the way from the port to the center of Athens.

A system of long walls, 500 feet apart, and said to be 11 feet high.

♪♪ But the building of the long walls and linking them to the city walls, like the section over here underneath the parking lot, you now had a total defensive system for Athens, defending both the city and its harbor.

To observers at the time looking at Athens, it now looked impregnable.

♪♪ The Athenians decided they didn't want to live in their rubble anymore -- it was time to rebuild, finally.

They wanted to build their city bigger, better, more magnificent, and more beautiful.

Ohh.

Everywhere you look, lots of chunks of marble.

It's incredible -- I'm driving on a road of marble chips.

They turned to this landscape in Attica, in particular Mount Penteli, where I'm driving, and they decided to take out the stone, the marble from here.

Beautiful white marble.

Pentelic marble.

♪♪ And the quarry that dates from that time is still here.

That is really impressive.

Feel like I stepped back in time.

I mean, this quarry is abandoned, but it's abandoned back from 2,500 years ago.

And I can see the tool marks, getting a sense of the precision that was involved, the organization, and the dangers, really, 'cause, I mean, this is a massive, massive quarry using, you know, pretty rudimentary tools.

It is just overwhelming to see all of this.

♪♪ Their rebuilding program that drew on the marble from here would give Athens a new identity... an identity fit for a city that was on the cusp of a new golden age in architecture, engineering, philosophy, politics, and culture.

A golden age that would make Athens the most influential city in the world.

♪♪ Our 3D model shows how the gleaming marble from Mount Penteli was used to create brand-new monuments on the Acropolis.

♪♪ First came the Parthenon, started in 447 B.C... then the propylaea, and a temple to Nike... and, finally, the Erechtheion, all completed in one remarkable 40-year burst of creativity and confidence towards the end of the fifth century B.C.

♪♪ [ Church bell ringing ] [ Man singing hymn ] ♪♪ I've come down to the heart of the old city of Athens, where archeologists discovered intriguing artifacts from a system that Athenians evolved to keep their democracy strong.

Dr. John Camp is one of the experts involved in the excavations that brought them to light.

-We're standing in what we think is the world's first public art museum.

Just behind it we found lots of ostraca.

An ostracon is just a broken piece of pottery.

These particular ones, these are replicas, of course.

Pieces like this were used in the ultimate in accountability for politicians.

Once a year all the Athenians could get together.

They voted -- is anybody aiming to overthrow the democracy?

And they brought with them their ostracons.

Scratched on it the name of the person they thought represented a threat to the state.

And the man with the most votes lost, and he was exiled for 10 years.

-And then today, you know, in the contemporary world, we used the word "ostracism."

-Yeah.

-That's from this.

-Yeah.

This is designed to counteract tyranny once the concept of democracy has been invented.

-It's a phenomenal thing, then, when we look at this and, considering that modern politics doesn't really work that way, maybe it's not a bad idea.

[ Chuckles ] -Accountability would be good.

♪♪ -With the system of checks and balances designed to keep power in the hands of the citizens, democratic Athens thrived.

♪♪ It became the dominant city-state in ancient Greece, and began to extend its influence across the Aegean.

Ah, look at that view.

My God!

Look at that.

I mean, this is how it's meant to be seen.

This is it.

It's this arrival from the sea.

It's very romantic.

-[ Laughs ] ♪♪ Cape Sounion is about 50 miles from Athens.

For a sailor who's returning to the Athenian territory after a trade or military expeditions, in the Aegean or throughout the Mediterranean, the first glimpse of that rocky cape meant the voyage was over and they were almost home.

♪♪ But something of a mystery has grown up around Sounion.

Thanks to the Temple of Poseidon that sits on the hill, it was mostly known as a sacred site.

And until recently, that overshadowed the strategic role it played in Athens' empire.

Thanks for having me.

Nice to see you.

How you doin'?

-Good.

-Great.

I'm really looking forward to... Now a team of archeologists, including Dr. Kalliopi Baika, are discovering how important it really was.

-There was a settlement with an important naval base, and part of it now, it's submerged.

Here is something from the building.

A huge one.

Actually, you only see part of a wall that is continuing in the sea, in the water.

-And this is massive architecture right here.

And this is leading then...

So why is it leading into the water today?

I mean... -'Cause we have a relative sea level change of at least 2 1/2 meters to 3 meters.

That means that most of the classical coastal sites are now submerged.

-So it's invisible but at the same time you know that it's there, so it's worth taking an opportunity to explore.

-You can see it yourself.

-Okay.

♪♪ It's only in the past couple of years that the importance of the site really has been understood.

-Here we have a strategic lookout post.

It operates in a network of naval bases.

That means from here a ship could reach the message to our friends that an enemy fleet is approaching, in only one hour.

♪♪ -The water is clear, but I'm having trouble finding the remains of the settlement.

-Yes, the vertical lines, the small structures, from this way.

♪♪ -And, finally, here they are.

Massive sections of the city wall, still recognizable after 2,500 years.

♪♪ And just beside them is one of the berths of the ancient naval base, cut into sheer rock.

And right by the shore are these fine marble blocks from what must have been impressive structures in this fortified outpost of Athens.

♪♪ Ah!

This is amazing.

You got a city submerged.

Look over here on the coastline.

I see part of a wall.

But underwater, it's massive.

It's about eight feet wide, and extends, you know, a pretty great distance.

♪♪ Fortified naval bases like Sounion helped Athens extend its empire through the Greek islands and into Asia Minor.

♪♪ But like every great empire, its ambition brought it into conflict with rivals.

♪♪ None more so than Sparta.

From the top of the cliff at Sounion, you can look out towards the territory of Athens' arch rival.

♪♪ Undemocratic, militaristic, and every bit as ambitious as Athens, the Spartans challenged Athenian supremacy.

They were at war here for 30 years.

Until the Spartans finally defeated Athens at sea, starved the city out, and in 404 B.C., forced the Athenians to surrender.

♪♪ The golden age of the world's first democracy had come to an end.

♪♪ Athenian democracy burned brightest for around just 100 years, but the ideas and achievements from this golden age would never be forgotten.

That was party thanks to the Romans, who arrived here in the second-century B.C.

They razed most of the city to the ground, but they spared the city's temples and architectural treasures, and over the next two centuries Athens became for them a kind of finishing school and cultural theme park.

♪♪ In the second-century A.D., the emperor Hadrian was one of Rome's most passionate admirers of all things Greek.

Behind me is Hadrian's Gate, and on the opposite side it says that Athens is the city of Theseus, the mythical king, but on this side it reads that Athens is not the city of Theseus -- it's the city of Hadrian.

♪♪ Hadrian was on a mission to improve Athens, and he lavished the city with gifts -- a library, a gymnasium, and something even more crucial to the everyday life of the people... ♪♪ a feat of engineering so remarkable that it was famous in the ancient world as one of the greatest achievements of its age.

♪♪ And I've asked rope-access expert Tim Fogg to help me investigate further.

-This is it.

-This is it, man.

I'm looking forward to this.

-So, this is the shaft.

-Yeah.

-It's impressive.

You can't see the bottom.

-Whew.

-So that's... You ready to go now?

-Ready to go, man.

Okay.

-Slowly... -Smell the humidity.

-Okay.

-Nice.

Whoo.

This is awesome.

Yeah, I feel like I'm descending to another world here.

I mean, it's... Say goodbye to the sky.

All right, here we go.

Whew.

Little more.

This shaft leads down to a second-century Roman aqueduct.

TV cameras have never filmed here before.

This is incredible.

Oh man, it's tight.

There we go.

♪♪ This space is tight.

I can't believe it.

After a shaft like that I imagined something a little bit larger.

I've stepped back almost 2,000 years into the time of the Romans.

This is incredible.

The water is still flowing right through here.

♪♪ ♪♪ [ Groans ] These channels are supposed to be the width of a man, but...

I can't hit this in the width -- I'm too wide, and it's definitely not my height.

♪♪ This water is crystal clear.

I don't know exact where I am, but I know where I'm headed.

I'm just gonna follow the flow of the water.

It's flowing downhill, towards Athens.

♪♪ This space is so tight and uncomfortable.

I can't imagine how unpleasant, how awkward it would be to work down here.

But, of course, how could you see what you were doing?

Right here there's a little purpose-built niche, and it's holding my flashlight today, but in antiquity they had oil lamps.

That's gonna produce a lot of smoke.

It's gonna be miserable work, back-breaking labor, and that's your only light source.

This network of tunnels took 15 years to dig out, work done by teams of men cutting through solid rock with nothing more than hammers and chisels.

This aqueduct is an astonishing piece of engineering, and I've asked ancient-aqueduct expert, Dr. Shawna Leigh, to shed more light on its construction.

What does it take to actually construct an aqueduct?

What's the engineering that's involved?

-The engineers would have to survey on the surface and then they would dig these shafts about 35 meters apart.

So, they would dig all the shafts along the route.

They would dig towards each other and the idea is that they're supposed to meet.

-Yeah.

I'm looking right here where I'm like...

I came over from this side and, oh, around the bend there you were, so it doesn't always match up.

-Yes.

It doesn't always match up, and so they have to adapt.

-And bringing this water in, what would it have done to the life of the people in Athens?

-You think of Roman bath culture.

-Mm-hmm.

-There were two Roman baths in Athens before this aqueduct was built, and after the aqueduct they had 35.

-So, life-changing for the average Athenian -- for everybody.

-Absolutely.

Absolutely.

Hadrian really made a difference in Athens.

♪♪ -I think it's actually getting more narrow.

The water is getting deeper.

It's up to my knees now.

[ Grunts ] All right.

This is the tightest spot yet, where the water's deeper and I'm having to go lower.

Really... Ooh-hoo-hoo!

The water is cold.

All right.

Yeah.

This is gettin', uh, a little more gnarly.

I think it's about four-feet high at this point.

I've got over my head this big brick tiles that have formed kind of like a pitched roof.

Ahh!

Another shaft.

You periodically have these shafts that are dug down so you can lift out the debris.

Yo, send it down!

Down comes the bucket.

I'm gonna load my debris that I cut through, soil and so forth.

They're gonna haul it back up.

And of course, when you were done tunneling for the day, you're gonna be hoisted up as well, if they don't make you crawl up.

It's an incredible enterprise.

I'm exhausted, and I've only gone through one small section.

[ Groans ] [ Grunts ] [ Chuckles ] Feels good to be able to stand up.

♪♪ The scans reveal the aqueduct in amazing detail.

This is one whole section, and we can see at both ends those remarkable curves where the workmen almost missed each other.

The length of the section we scanned was 90-yard long, and the water level drops just over a foot across that distance.

A gradient so precise that this aqueduct was used until the middle of the 20th century.

♪♪ But this was just one of four major aqueducts dating as far back as the sixth-century B.C., that stretch over 50 miles, bringing vital, life-giving water to the city of Athens.

♪♪ Of all the cities in the ancient world, Athens excites the imagination like no other.

Democracy is the gift this city gave to the world, two-and-a-half-thousand years ago, and it matters as much today as it ever did.

-Another beautiful green space for you.

-Good to be here.

Now, I'm going to explore the Acropolis in a new way.

-Let's go.

-Can't wait to see this.

-So, welcome to the Acropolis.

-Nice.

Matt's team has stitched together thousands of high-definition images... Ah, man.

That is intense.

...to make a model of the Acropolis that I can experience in extraordinary detail.

♪♪ Yeah, and if I come down over here into the city and I'm looking up at it... Oh, it's just gorgeous.

Yeah.

It really is.

Closer up it's just really something special.

-So, here we are.

The perfect doll's-house model of the Erechtheion, right?

-This is amazing.

Now I can really... -...Go on through.

I mean, get yours-- There's no rules anymore.

You can step wherever you need to.

-And -- Oh, and I can just pass right through, and I can see all the different elements, and it is like a little doll house, isn't it?

It's incredible.

All this rich detail.

The real thing.

Huh.

That's funny.

[ Both laugh ] Below the ground level of the northern porch.

-Yeah.

Right.

So, you're... -Sneaky.

I'm stuck.

We're trapped.

I can't get out.

I mean... -The world is at the right scale.

This is one-to-one.

-We can look up and there's our opening in the coffered ceiling.

-Should we try to find another super privileged spot within this... -Oh, yeah.

Whoa.

Oh, we're outside now.

-Ah-ha-ha!

-Yeah.

Wha-- -We passed through that main space, and then watch out.

Comin' at us.

-Oh.

Gettin' the caryatid porch.

Whoa!

Now I made it.

-Yeah.

-Fantastic, there.

-I mean, this is... -What a view.

-These poor caryatids have been holding this load up for, what, two-and-a-half-thousand years?

-[ Laughs ] A long time, yeah.

-Maybe it's time you jumped out there and gave them a hand, Darius.

-Oh... all right.

Now I'm... now I'm with the ladies, right here.

And... That is amazing.

This is, like, one-to-one scale?

-This is one-to-one scale, yeah.

So, they are actually quite big, no?

-They're pretty massive.

-Yeah.

Go on, then.

Give us some fingertips.

Poor... Give them a little hand.

-Almost.

I'm a little too short, but you get the idea.

Yeah, that's over, you know, two meters, then.

-So, you think you can hold that position for another two-and-a-half thousand years?

-I can give it a try.

It's a pretty amazing spot to be in.

♪♪ I think it's really here that you get that strong connection between the mythic past and the foundation of Athens and the ideas of the golden age of democracy of Athens.

It's quite a view.

♪♪ ♪♪ The Athenians forged a new world.

They turned silver from their own mines into a fleet of war ships to protect their city and its democracy.

They surrounded their city and their harbor with extraordinary walls, and they created a unique identity for Athens using marble carved from their own quarries.

♪♪ This bold democracy left a legacy that has never been forgotten.

♪♪ It's so easy when you come to Athens to be overwhelmed by all the ancient monuments on the Acropolis, like the Erechtheion and the Parthenon, but it's become clear to me that it's in the hidden and invisible places, like the aqueducts and the mines, that that is where Athens itself was forged.

That's where its dreams and ideas became real.

Those same ideas and dreams that are fundamental to our lives today.

♪♪ ♪♪ -"Ancient Invisible Cities" is available on DVD.

To order, visit shop.PBS, or call 1-800-PLAY-PBS.

This program is also available on Amazon Prime Video.

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