This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

An homage to everyone's favorite prehistoric cartoon family.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This small interfaith chapel lies not far from the rim of the Grand Canyon.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

This unique historical monument features large concrete spheres designed to resemble fallen stars.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

Once forgotten and built over, this historic Black cemetery now houses a poignant memorial.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

The narrowest house in America is seven feet of pure spite.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

A giant ball made from pieces of an old Jeep.

This spot memorializes one of the greatest plays in NFL history, unless you happen to be a Raiders fan.

Meet your friends, marry your true love, or tell your enemies to kiss your butt under this historic Pittsburgh timepiece.

Color-coded signs direct drivers on a network of routes designed to avoid Pittsburgh traffic.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

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

Prone to disastrous fires, the city of San Francisco has the Guardian, a fireboat gifted by residents, to watch over them from the bay.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

A monument to the love people have for their pets.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.