South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

The graffitied ruins stand hidden within the Pennsylvania woods.

On this island, you suck away your garbage via an elaborate pneumatic tube system.

This beloved marketplace mascot poops money and grants good luck.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

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.

During the 19th century, you could pay for violence off a prix fixe menu on this Manhattan street.

These medicine cabinet staples are part of the museum's collection of everyday objects.

The abandoned coal loading dock is a canvas for unsanctioned art.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

A forgotten relic from New York's bygone trolley system hides in plain sight under a bridge.

Site of the first pathological and bacteriological research facility in the United States.

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.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The bombed out remains of the old church were kept intact next to the new one, as a reminder of the futility of war.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

Enjoy a slice while browsing the world's largest collection of pizza memorabilia.

Memorial to the 137 lives lost on a ship fire, the whole hulk of which washed up on the Asbury Park shore.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.