Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

The Underground Railroad passed right through this historic Brooklyn Heights church.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

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.

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

Unrepaired walls from a 1920 anarchist bomb attack.

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

The site of the deadly Triangle Shirtwaist Factory Fire.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

The middle finger of modernity.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

The only museum with its curator—and her pets—buried inside.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.