A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

An incarceration museum on the spot of possibly the oldest prison in England.

This one has sailed five times as far as Sir Francis Drake's famous ship.

An architectural oddity hides in plain sight on this iconic London bridge.

A hands-off space for graffiti artists to hone and display their skills.

One part local history, 99 parts gruesome haunted house.

Where British troops serving on the remote islands paid tribute to their faraway hometowns.

An ever-growing field of footwear invites legends and more shoes.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

A painfully obvious spy house sits right across the street from the Russian Embassy.

This grand gothic brewery has been pumping out suds for over a hundred years.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The United States Capitol's former columns still stand.

A 300-ship graveyard, with a few still visible at low tide.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

An essential stop before plundering, BYO Cutlass.

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

The site of the "Bone Wars" between two rival paleontologists during the dinosaur rush of the 19th century.

This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.

Eat like pre-Columbian Native Americans in this New Mexico restaurant within the Indian Pueblo Cultural Center.

A museum dedicated to the alleged Roswell Incident.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.