The top of a giant mesa, just outside of Amarillo, appears to float in the sky above.

The stones that traveled from Spain to eventually become a holy place for San Francisco's nature worshippers.

Golden Gate Park's historic collection of plants.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

San Francisco's newly reopened hands-on science museum.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

The palatial McDonald's that inspired Wesley Willis.

Illegal drag racing two stories beneath Chicago’s streets.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

A hot dog stand where the heads are just as hot as the dogs.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

Historic funicular railway, believed to be the shortest railroad in the world.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

The abandoned zoo enclosures offer a perfect place to experience the other side of the bars.

World's largest collection of serial killer artwork and other macabre exhibits.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

A former major munitions plant that has been converted into a sprawling art space.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

An astounding collection of medical specimens, including bits of President Lincoln.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The romance of early commercial flight still fills this Art Deco destination.