This unique and iconic city was founded in the fifth century and lies on more than 100 islands in the Venetian Lagoon.

Environmental scientists Jane Doe Mostow has lived here for over 20 years, but this is a UNESCO World Heritage site.

Um, Venice has an architectural style that you can't find anywhere else in the world.

Built centuries ago, Venice is an engineering marvel.

The foundations of it were built using wooden piles in marsh and sand.

It still stands.

Today is one of the world's most iconic cities.

Venice was built on millions of closely spaced wooden poles 18 meters in length, hammered through soft mud into the solid clay below.

Protected from oxygen would doesn't rot and in fact, thanks to the mineral rich waters becomes petrified or hard like stone.

The foundation might be solid, but there's no getting away from Venice is low lying and wet Location.

Venice is on the ocean on with these huge tidal surges and rising sea levels, it's a recipe for disaster between autumn and spring.

Venice experiences abnormally high tides known as the aqua alta.

These tides air made worse by strong seasonal winds.

The impact could be devastating, something residents like engineer Vincenzo di Tella know all too well when there used to be some type.

The Venice is completely flooded.

It's not possible for the normal activity.

It's only possible to go with boats inside of the river, but you can have to go on the street.

Tidal surges have long been a problem for Venice, but in 1966 it had the worst flood in recorded history, and the government finally decided something has to be done.

Theatre Alley in government, pledged a solution.

But it wasn't until the 19 eighties that the most say project was conceived, most say was named after the Old Testament prophet Moses on.

Like its namesake, the plan was to hold back the waters that were threatening to engulf Venice in the 19 eighties.

Then the Italian government began to prototype a title barrier that could rise when it was most needed.

When they're the largest tidal surges, most say would be an engineering project on a biblical scale.

They use that term still because of its reference toe.

Moses, who parked parted the water as though this engineering project is going to have the same kind of universal powers.

Thio defeat the physical forces of the world after decades of discussion, design and prototyping.

In 2003 go ahead to build the barrier was finally given.

Aim of this ambitious project was to divide the Venetian lagoon from the Adriatic Sea by placing barriers across three inlets.

A total of 78 mobile gates needed to be laid at the bottom of the sea bed.

Each one is 28 meters long, 20 meters wide and weighs a colossal 300 tons.

Mostly consists of a series of gates that lie flat on the seabed and their hinged at one end and to activate them.

Air is pumped into the gates and through the principle of buoyancy, the gates rise up, providing a barrier between the Venetian lagoon on the Adriatic Sea.

The design was revolutionary and would allow authorities to open and close the sea gates cope with title surges of up to 2.7 meters.

At least that was the plan.

But to match the biblical scale of this project, the catalog of catastrophes has been almighty as well, becoming a joke amongst Venetians.

So what they didn't think about was that when the barriers up tidal forces come push sand and silt underneath the barrier so it can't sit back down properly.

Engineers realized that when the gates were raised, sand would settle in the trenches, which meant that when the gates were shut, they couldn't close.

Probably, materials used in the construction of the barrier have already shown significant signs of wear.

Another really difficult problem is corrosion.

The gates that were installed underwater are already showing huge signs of corrosion, and gates that haven't even been put in yet that are on the land are starting to rust.

So this is going to render them much, much weaker and can lead to huge mechanical failures in the future.

Barriers are made out of these big metal panels, and that pain is being corroded.

That's also something that you know is a well known feature of salty water.

The gate, sir corroding even the replacement gates a corroded.

Clearly, they chose materials that just couldn't withstand saltwater and sea air toe.

Add insult to injury.

A tiny Venetian resident is causing huge extra problems.

What they didn't also think about was the environment department of See.

There's lots of muscles and all sorts of creatures down there.

They start to live on the brackets on the hinges, meaning that sometimes these hinges or inoperable.

There was some issue with hinges.

And lo and behold, there were muscles growing on the hinges.

And the only way to deal with that is toe have divers go down and literally scraped them off, which it just seems ridiculous.

All these massive oversights have Venetians up in arms they're still trying to finish.

Building.

That was plan in the eighties was supposed to be finished in 2000 and 11 and they recently said that the 31st of December due date might not be possible with no end in sight.

This project also comes with a hefty and ever growing price tag.

Latest estimates take the budget to a whopping five billion euros, three times the original estimate.

It's already cost billions, and it's not even finished, and to maintain it is gonna cost 80 million euros a year.