What once sat in the world’s spotlight is today a largely disused ghost complex.

Two stone columns flank the grand Venice square, but there were supposed to be three.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

Go inside to really appreciate this 500-year-old technological masterpiece.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

An ancient knight and a symbol of the city's freedom.

A tiny church on a man-made island in the Adriatic.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

Ride the subways of yesteryear.

A popular European tradition makes its way to the states on one of America's most famous bridges.

Magnificent New Deal Murals evoke a time when New York City harbor was one of the world's greatest and busiest ports.

The home of the first American-born saint is one of the only curved buildings in New York.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

Twice a day one of these tragic bronze mariners drowns with the tide to remember all those the sea has taken.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Elevated freight railway turned wildly successful urban park.

The greatest real estate coup of all time.

The competition: breathe deeply as long as you can.

The site of the deadly Triangle Shirtwaist Factory Fire.

One of only two commuter aerial tramways in the United States.