This narrow Ghent alleyway is an officially sanctioned street art tunnel.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

A condensed piece of China floating in a Dutch harbor.

Alexander Hamilton’s creation caused quite a bit of controversy.

The smallest island in Manhattan is a manmade landfill dominated by a Buddhist peace arch.

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

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

A crumbling hospital from the 1850s on Roosevelt Island.

An eerie diorama that captures the majestic nature of a few prehistoric-looking beasts.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

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.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

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

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

Lie in a hammock where George Washington stood.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

In its day this historic fort held 100 cannons pointed in almost every direction to protect New York.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.

These murals have been brightening a Chicago beach for more than 30 years.

The last remnants of a lakeside airport that was bulldozed overnight by the mayor of Chicago.

What might be the oldest living tree in London has survived fires, bombings, and estate agents.