The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

A fantastic array of trays and cables once whisked books over to the Capitol at 600 feet per minute.

100 years later, they're still down there.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

Decades before the scandal, this staircase on the river was a literal "water gate."

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

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

A whimsical cottage from the 1300s with a preserved Victorian-era post office inside.

This short white tower is all that's left of Scotland's first permanently manned lighthouse.

You'll never meet anyone this passionate about elephant droppings.

This early version of the guillotine was used to execute the man responsible for its construction.

One of the world's tallest statues is also one of its most hated.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

A statue of a boy looks up at where the famous rival to the Leaning Tower of Pisa once stood.

A 6th-century stone lies at the site of the mythical battle waged between King Arthur and his nemesis Mordred.

Banksy's image of a naked man dangling from the window of a sex health clinic.

It is said the legendary wizard once lived in this sea cave beneath Tintagel Castle.

Holding multiple historical boats and an entire 19th century village, this New England attraction is the largest maritime museum in the world.

This small-town pizzeria won the Hollywood lottery.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

The oldest housing complex in Riga is a mini timeline of architectural trends.

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