Located in the remote Monitor Valley, this travertine bowl contains a scalding pool of water.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

Mine your own precious stones.

In 1909, the steepest and most difficult piece of track on the Canadian Pacific Railway was replaced with a series of spiralling tunnels cut into the mountains.

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

This small archipelago in northern Lake Superior was formed by a massive meteorite impact 450 million years ago.

The last remaining building in Washington, D.C., built by H.H. Richardson, one of America's most iconic architects.

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.

‘Bush the old fire dog died of poison July 5th, 1869. RIP.’

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

The house where John Wilkes Booth conspired with his co-conspirators.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

The stone circle honors the 19 firemen who perished during the Yarnell Hill Fire.

Arizona's first government hub is a rustic cabin now preserved as part of a historical museum.

One of the largest private collections of cars manufactured by the short-lived Franklin Automobile Company.

This ancient trail has claimed the lives of over 2,000 people.

The largest copper mine in Arizona, this enormous open pit emerges from the hills like an alien landscape.

An off-the-beaten path cave with an underground lake.

A bizarre house filled with an astounding array of collections.

This remote Colorado canyon is home to the second-largest collection of natural arches in the world.

An interesting look into 18th-century American history.

16,500-acre ranch filled with American heritage, geological wonders, and a giant pile of tires is the crown jewel of an intriguing tug-of-war.