One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.

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

The very center of Paris is surrounded by a bevy of strange good luck rituals.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

Rising from the sea like a stone monster.

An acoustic anomaly with a mysterious cause.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

This geothermal hot spring hides beneath a slowly growing mineral dome.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

A submerged archeological park still holds the wonders of a Roman Sodom.

Famously misunderstood wonder of the ancient world

This frequently-photographed waterfall takes only a short hike to visit.

Two thousand artifacts from around the world collected by one woman who loved to travel.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

Towering basalt columns, a creation of fire and ice.

Take a drunken tour inside the world's largest known geode.