Venice's Hidden Foundations: The Secret World Beneath the Canals

So, Gianluca, where are we? This is the Bourbon tunnel. Yeah. So, this is the escape tunnel Yeah. for the king to go from the palace Yeah. in the Piazza del Plebiscito Yeah. to the barracks. to the military barracks. Wow. [groaning] The king was very worried, Ferdinand II, so he decided to dig a tunnel. But this is a huge tunnel. You don't Because it was a king. It's so big because the Bourbon tunnel is joined together all the tufo quarries under here that had helped to build in Naples. And its uses didn't end there. After World War II, it was even a dump for abandoned vehicles. As our scanning team begins the task of

making sense of this labyrinth, we're going to look at what went on down here during the Second World War. Come with me. I want to show you something from the World War II. A bomb shelter. Naples was the most bombed Italian city in World War II. It's estimated that Allied raids killed more than 20,000 people. Look there. We have found the beds, the original. And the toys for children. Oh. Look. Come in me. You can read alarm 26 April '43 and here Noi vivi.

We are still alive. Because it was better to stay than stay outside under the bombing. Nearly 200 km of tunnels were cleared and electricity cables laid to cater for the hundreds of thousands of Neapolitans forced to shelter from Allied bombing. But life went on. When we dig here we found this Oh. green color, as you can see. As you can You sure you want to be doing that? Try, please. Don't be afraid. Is that hair lotion? Yeah, a very old That's like when you go to the old barber shop. Exactly. How Se- 70 years old. 70 years?

It works. But it hasn't changed. Yeah. Do you use it yourself occasionally when you're down here? No, that's I prefer not. Okay. That is extraordinary. Yes, very nice. I love the fact that this tunnel was originally built to save one man, a king. It never did, but it actually it ended up saving thousands of people as a bomb shelter during the Second World War. I've come to the heart of the Campi Flegrei, to the Roman town of Baiae for my very own introduction to the underworld. In ancient Roman times,

this was known as the Agora or the workplace of Hephaestus or Vulcan, the god who worked with fire and lava to create the great weapons of the gods themselves. Hercules was supposed to have come here and defeated the Titans. And you can imagine them seeing this all around them, boiling lakes of mud at over 200° C, sulfuric streams spewing into the air. This was where the Romans came to get just as close as one would ever want to do to the underworld. I'm working with a team of speleologists.

They're going to take me into a man-made tunnel that when it was discovered in the 1960s was thought to be the mythical entrance leading to the river Styx. I'm quite looking forward to this journey into the underworld. In the ancient Greek and Roman myths and stories, it's only the mad, the bad, and the utterly heroic that decide to make this journey. It's the fact that this is not only going into the earth, into the hillside, but it's going down at the same time, isn't it? You really do feel like you're traveling down into the center of the earth.

It does feel like being in somebody's armpit. I'm now having to go definitely with my bended knee and my bended back. This really does feel like it could go on forever. And the temperature is definitely rising. The geothermal energy of this incredible area of the world is so seismically active, so on the edge of tectonic forces that have shaped this landscape. We're going down at the same time, down, down, down. But who knows who is waiting for us at the end. You really want to let a sleeping giant lie.

You don't want to be the one who wakes it up. Well, here we are finally arriving at the river Styx. I have a chance to put my hand in the waters. I hope it isn't the fabled river forgetfulness of the underworld. Ah. Tepid here and you can see that the water stretches far back. They dived this when they first discovered it in the '60s and found the hot thermal springs that turned this water into a very warm, well, 60° back then, but nowadays it's more in the high 20s. You can understand coming here why people would have thought in ancient times that this might be one of the routes into the underworld. But in reality, I think there's a much more simple, but also satisfying explanation.

The ancients thought it was easy to get into the underworld, but much more tricky to get out. So, I'm relieved to make it back to the surface. This is going to be special. I've never seen the treasures I've been promised down here before. This is Baiae's lost harbor, where the notorious Caligula is said to have reacted to a prophecy that he would never be emperor until he rode on horseback across the water of the bay by tethering 4,000 ships together from this harbor wall and trotting across. That was my first sighting of the Portus Julius. What's magic is that you can follow the grand monumentality of the lines, the solid masonry that's still there, straight out at sea and then across the bay. You can imagine that those walls

doing a pretty good job at protecting the fleet. Now I want to experience the posh villas, and as these watery gems have sunk even deeper beneath the waves, I'll need to scuba dive for this. This is absolutely incredible. I could do with a little champagne, I think, at this moment in time. So, we're in one of the rooms of one of those posh fancy villa owners. And I am currently in the process of uncovering this gentleman's mosaic floor. If only this mosaic could talk. The mosaic floor isn't the only treat. The statues in this Roman villa are now faithful replicas so that enthusiasts can still share the magic of this lost world.

There was a wonderful story that in this dining room there was a channel of seawater that the plates of exotic food floated on around the diners. It was the yo sushi moving belt of the ancient world. So, there's a wonderful irony that now this is itself underwater. And the fish that once graced the tables now rule supreme down here. I absolutely love it. This is the first time that I've been able to see this underwater world lost in time, wrapped in silence as the sea levels have risen and the earth has fallen.

What a great place to explore. a team of underwater archaeologists and restorers who are repairing a section of canal wall. The visibility is not currently fantastic. It's uh incredibly disorientating. The team has timed my dive at the turning of the tide. As the water starts to rush out of the lagoon, it takes some of the silt with it. We're starting to get a little bit of clarity now down here, which is really exciting. So, I'm pressed up just against the canal wall, the deep stone foundations under the building. As the water clears, it reveals the invisible foundations of the Venetians

amphibious city. What we're looking at here is it's an exposed tops of tree trunks. These ones here are in fantastic condition. It's hard to believe this is wood from that is hundreds of years old. The early Venetians took massive wooden trunks between 1 and 1/2 to 2 to 3 m long and they pounded them into the mud along the boundaries of the area they wanted to build on. Now, that secured the mud and gave them the beginnings of a strong foundation. But, obviously, normally wood would not survive. And yet, here's the miracle.

Thanks to the anaerobic conditions deep in the mud where there's no oxygen, these tree trunks don't rot. The exterior walls of Venice's streets and palazzos are supported by thousands of tightly packed wooden piles thrust into the mud of the lagoon to shore up the city's precious land. It's an ingenious piece of engineering that's kept the city afloat for hundreds of years. Paolo Zanetti and his team are tasked with ensuring it lasts into future centuries. Now, the 30,000 boats rushing around Venice every day are exposing the piles. The wash and the underwater waves from propellers are destroying the canal walls.

We need to go back to road boats and everything would be grand staircase entrance in the Doge's Palace and the smell of power is reeking in the air. You've got the god of the sea, Poseidon, greeting you on the right to the god of war, Ares, on the left. And then above us, the winged lion of St. Mark of Venice. There's no way that you couldn't be impressed, overwhelmed by this place. But, it's an odd one because it looks like a palace fit for a king. And yet, the ruler of Venice, the Doge, was no king. In fact, Venice had a very complex system in which no one person was trusted with absolute power. Indeed, despite being a powerful place that dominated the world, it was terrified of giving power to any one person.

Our scans uncover the labyrinthine internal structure of the palace. It reflects the Venetian Republic's complex political structure that evolved over these centuries. This is the room where the Venetian leaders gathered to elect the Doge. He would then hold the position for life. Then there are grand halls for overlapping and competing bureaucracies diluting his power. There's the Senate, the College, the Council of 10. The members of these bodies and the Doge himself were all drawn from the most important assembly of all.

Welcome to the Chamber of the Great Council of the Venetian Republic. 53 m long, 25 m wide. It's the largest room in the palace. Yet, more than that, it's the largest room in pretty much any palace or headquarters of state anywhere in Europe. The Venetians knew how to build big and build impressive. But, what I love about this place is the way it symbolizes both how Venice saw itself and the complex checks and balances in how it ran itself. So, along the tops of the walls here are portraits of the first 76 Doges, the leaders of Venice, the chief magistrates of the Venetian Republic. But, just in case anyone forgot that the Doge was not all powerful, there is this, the black curtain covering the Doge who tried to go too far. Not only was he executed, but

evermore given damnatio memoriae, banished from memory, and yet kept in because the Doge was sitting right there opposite with this constantly in view just to remind him. And frankly, that was probably the last reminder he needed because in this great hall is the Great Council, the members of every patrician family in Venice, the male members. So, something like 1,200 to 2,000 people who saw themselves as the bedrock of the Venetian Republic, the people who were there to keep guardianship of the laws, to keep the Doge in his place, and to make sure that the Venetian Republic continued on track. isn't going to get me into trouble at home. So, this is one of the most famous of the casinos from the 18th century. Casanova would have been here.

And what does one come to one of these little casinos to do? Uh gambling and sex. Gambling and sex? In equal measure or in the same place? Gambling is the main thing. The rooms there were beautiful women came here, beautiful courtesans. So, it was basically devoted to pleasures of every kind. Uh as you can see, it's beautifully adorned. By the 18th century, uh the population of Venice was 100,000 people, men and women. And there were 12,000 prostitutes. Over 10%. Over 10% of the population. Now, the courtesans are the finest of the creme de la creme. They're the ones who become extremely wealthy.

They're the most sought after. They would go to extraordinary lengths to make themselves beautiful. They would wash their hair in urine so it would have a sort of a Wow. I mean, I'm used to it from the ancient Roman perspective that you literally you use urine to wash your clothes in because of the ammonia kind of cleans everything out. But, washing your hair seems to be a whole different level. It would actually give them a sort of a reddish golden tinge that was very fashionable. So, it's dying then. It's it's a And the smell? I think if you washed it out, it was all right. But, but the main thing was the fashion. These extraordinary outfits that they would wear, these very low-cut bodices, these with veils. Uh

and also these shoes, these extraordinary platform shoes. And I thought the Spice Girls had been through here. I swear these had come from. What shoe size are you? You can try them on. I'm an 11. So, I don't know I don't think I can fit into it. I just want to see what they Let's go. What's going on here? You can do it. All right. My hand. Why god, I mean, well, you can certainly see everyone in the crowd. Like and I guess they can see you, right? It's part of the purpose of the shoe. Yeah. You've got that lovely urine-stained hair and they'd make a

bee line to your A bee line, yes, absolutely. And then they'd come to about here and basically stare at your boobs for the rest of the uh evening. Casanova had over 100 casinos to choose from in the city, but he would have to be on the guest list. All right, Michael. So, let me in. Oh, you can. Hello. So, as you can see, it was just like a speakeasy. If there was a bang on the door, you could come in and you'd look down and you could see who was there. If it was someone if it was the someone you didn't want to see, uh

someone's husband, there was a secret exit out the back. So, you could see who was down here and just get out of there if you needed to avoid them. I don't think we'll let this one in. And it really does feel not just so far away, but just so vast, so enormous. It's the largest dome in bricks and masonry anywhere in the world.

The dome spans 45 m. It makes you look up to heaven, but keeps your mind firmly on hell. But, we're not here simply to stare at beautiful things. We're here to get underneath their skin. And to do that, we're going to have to go behind the scenes. Just as well I don't suffer from vertigo. Florence's cathedral was dreamt up in the 13th century to show off the city's growing power. But no one knew how to build a massive unsupported dome. The knowledge had been lost with the Romans. For 140 years, this balcony was the highest you could climb. The end of the cathedral stood open to the elements.

Finally, a committee of the greats and the goods, including a Medici, of course, held a competition to find someone who could solve the problem. The man who stepped forward was Filippo Brunelleschi. He offered a design that was a piece of sheer theater and magic. And quite literally, because Brunelleschi refused to share with the committee the exact plan of how he was going to achieve this magic. He asked them to trust him. There is a wonderful story, and it revolves around the humble egg. Brunelleschi said, "Okay, all the competitors, can you make this egg stand up on a plate? If you can, build the dome."

None of them could. Brunelleschi came along and quite simply cracked the egg on a plate. Now, his competitors said, "Well, if we knew you were going to do that, we could have done it, too." Exactly the point Brunelleschi applied. "I'm not going to share my magic with you. You're going to have to trust me that I can do the impossible." So, Brunelleschi, who never built anything before, got to build his dome. But he still refused to reveal his plans and deliberately left no blueprints. And no one could work out how he did it. It's incredibly disorientating walking up. Your body wants to compensate in that direction, which means you're

leaning onto the wall at the same time as you're spiraling round in a circle and going upwards. It's ah, it's good to see some daylight and get your sense of direction and space again. The tower is eight stories high with its famous lean just under 4° off center. Our 3D scans reveal a skeleton image of the tower, and it can help us see how the medieval builders tried to correct the lean. Things started to go wrong almost from the word go. After just three stories had been completed, it became clear the tower was leaning. Soft clay and sandy soil had destabilized the foundations.

Work stopped for almost 100 years. But then they tried a novel solution. They made stories four, five, six, and seven shorter on one side to try to compensate for the lean. Incredible. Sense when you climb this building is one of both human fallibility. They didn't realize that the foundations were on sinking ground, but also perseverance. For 200 years, the Pisans were trying to make this tower work, building little by little until finally they got to the bell tower on the top. The Pisans never gave up trying. In one last attempt, the top itself was added at a jaunty angle to the rest. At least the Pisans had completed their tower. In 1372,

Florence's cathedral had stood domeless for 76 years. How are you? Monica Bietti is the director of Michelangelo's Chapel at San Lorenzo, and her enthusiasm for the place is infectious. So, this is the work of Michelangelo? Yes, all the work of Michelangelo. The architecture, the sculpture. These are I mean, obviously very famous sculptures now of Michelangelo. Can you tell me a little bit about them? I explain to you. This is the night. The night look like the moonlight. Yes. Look the marble. It's shining. shining and it is so white. Like the moonlight.

This is the day. What I think is that this is the beginning of the day when the shadow are not definitely. I like it. I love it. I like it. I like it a lot. But this is very unusual for a sacristy. These kinds of Yes. personifications, night and day. Are these representative of Michelangelo's view of the world, of the cosmos? Uh Michelangelo and also Medici. Because this kind of chapel is like a symbol of the life that finish, you know, but the art remain. And the art of the Medici remain for all the time. Unlike the marble sculptures, the relationship between the Medici and Michelangelo didn't stand the test of time. In 1527, the people of Florence rose up against the Medici, and they were forced

into exile. Michelangelo refused to go with them. The great artist stayed in Florence and joined the rebels. So, Medici the commission Michelangelo to build this Yes. and to sculpt these buildings. Yes. Then the Medici are expelled from the city. Yes, right. Michelangelo then takes the side of the city, of the Republic of Florence, against the Medici. And then the Medici come back to take power, and now he's their enemy. And so he was really afraid. Michelangelo remain in a secret space for 3 months. But nobody knows where. So, do you want to see? do. I can show it to you. Where do we go?

There. Where are we going now? Oh. Down there. Down? This is a door. Yes. So, this is where Michelangelo was hiding. Yes. This is not somewhere the public can go. Oh, no. This is really secret. It remain open. We won't get trapped. Yes. Feels like we're underground. Yes, but look on the left, there is a window. This? Yes. Michelangelo wrote that he hid in a tiny cell, entombed like the dead Medici above, though hiding from a live one. "To forget my fears, I fill the walls with drawings." For over four centuries, nobody was able to find where this tiny cell was.

Then, in 1975, during some building work, this little room was discovered. This is the way down. The authenticity of the drawings has been debated, but many, including Monica, are convinced they're the work of Michelangelo. But this face, I recognize this face. I know it as a classical art. This is the Laocoön. Yes, it is. This is the sculpture that Michelangelo discovers in the ground in Rome and Do you recognize this one? What is? That's the David. Of Michelangelo's. That's his foot. Yes. And that's the one that got hammered off. In every part you can recognize the thing that he did. It's like an autobiography through art of his life and career today.

When you are terrified for your life, hiding in an underground chamber, Yes. it's incredible.