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

A little slice of Florida face-in-a-hole kitsch, unexpectedly located in a small New Mexico town.

This sparsely populated town offers a look back in time.

A natural formation that resembles a camel resting in the New Mexico desert.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

The oldest continuously occupied public building in the United States.

A 56-foot tall statue of the god of fire looks out over Birmingham, Alabama.

These beautiful wineries were at the center of Lake Erie's "grape belt" back when the Midwest dominated American wine production.

Underneath this water pump, Annie Sullivan helped Keller speak her first words.

These "mermaids" that surround a plaza in Segovia are rather sphinx-like.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

This influential Renaissance-era library was once the haunt of kings and monks.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Artist Natividad Sánchez wrote a new ending for one of Roman mythology's tragic love stories.

A historic landmark and museum filled with curious objects representing the history of Key West.

The museum chronicling a treasure hunter's dream, fulfilled.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

"We Seceded Where Others Failed."

A monument celebrating the idea of reaching inaccessible places.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

This is one really big nut.

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