One man's lifelong obsession with death.

The mysterious canine hides atop a drain pipe on the back of the building, some say as a sneaky shoutout to Yale.

This tiny structure was built by the creator of the Brooklyn Bridge.

A bronze monument to the infamous radio broadcast in the real New Jersey town where the fictional Martians crash-landed.

Step inside Lucy, the world's largest "elephant."

An unusual assortment of steerable wooden sleds is on display in a library in New Jersey where they were first invented.

The first partially complete dinosaur skeleton was discovered here, forever changing the world's view of the ruling reptiles.

The final resting place of one of the United States's greatest poets.

A completely round house designed for the Atomic Age.

This historic iron-working village is now a ghost town so immaculate that it looks as though it was recently built.

In the woods of New Jersey lie the ruins of a munitions village abandoned after World War I and the remnants of a 1920s wooden racetrack.

Thousands of Matchbox cars spanning generations call this New Jersey barn home.

This Great Depression-era creation was once known as the strangest house in the world.

This little-known Revolutionary War fort is supposedly haunted by the ghosts of its past.

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

Where America's first doomsday cult awaited the end of the world.

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

A daily replay of the experiment that proved the rotation of the Earth.

This beloved marketplace mascot poops money and grants good luck.

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

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

These beautiful ruins deep in the Pennsylvania woods are thought to have been a ski lodge or a speakeasy, but no one really knows.