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

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

Florida might be at its most surreal in this museum devoted to the famed Spanish artist.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

A walk through the historic city center, under the streets of Seattle.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

These light, hollow rolls have been linked to Acadia National Park since the 1890s.

A tribute to Ponce de Leon's supposed quest for eternal youth.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

A building so large that it has its own weather.

Measuring approximately 200 feet long, Swampy is the world's largest alligator-shaped building.

A vast array of tropical plants collected by a vacationing couple.

If you don't look closely, you might mistake this sculpture for just another passenger waiting at the airport.

Allegedly haunted by Walt Disney himself, this inconspicuous lamp is always kept lit in his honor.

After the attack on Pearl Harbor, rocks and fossils from every U.S. state were collected into a pyramid of national unity.

Electrical pylon in the shape of Disney's beloved mouse.

A glimpse at Walt Disney's vision for a "community of tomorrow," in miniature.

Opened in 1976, this monster-sized version of the fast-food franchise is sometimes called the Epic McD.