Cathedral carved out of salt, located a mile below the Earth's surface.

An exquisite and eclectic selection of African masks stands out within a massive woodcarving marketplace.

The world-record holder for the longest bridge stretching continuously over water.

A quirky collection of old chairs fills a random vacant lot in suburban Texas.

Not only does this shop sell mokorotlo, the traditional hat of Lesotho, the building is shaped like one.

A short but powerful waterfall resides amid Colorado’s Great Sand Dunes.

Legends surround this jagged rock formation in the New Mexico desert.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

A house carved into a rock in the 1940s.

This 19th-century ranch is being transformed into a residential library with thousands of books about the natural world.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

This bewitching Babylonian goddess haunts a hallway of the British Museum.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

This ancient Egyptian obelisk still bears the wounds of World War I.

The bronze uniforms commemorate the vital role of women during World War II.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.