Sitting in a lagoon on the edge of the Adriatic Sea, Venice is made up of 118 islands, connected by over 400 bridges. More than 16 million visitors are drawn to this Italian destination each year – but the city is under siege. With rising sea level it is gradually sinking and parts of the city flood 250 times every year. How did Venice come to thrive in such an inhospitable place – and how will it survive today? This film looks beneath the city’s skin to discover the engineering wonders that allowed the city to grow. Stunning CGI animation peels bricks and stone from its historic buildings and drains its waterways. The city’s leading engineers and geologists reveal the secrets that keep Saint Mark’s bell tower from toppling. We join a team of divers on the first underwater inspection of the 400 year old Rialto Bridge and explore how Venice’s new flood barriers are being built.