Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Village situated on a narrow volcanic escarpment.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Science fiction's grandfather has a fittingly marvelous tomb.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

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

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

Recently restored menagerie of Victorian-era beasts.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The remains of a grand castle that may have inspired Bram Stoker's Dracula.

A cozy bookstore is tucked within an old gold mine shaft beneath the cafe and ice cream shop.

Towering basalt columns, a creation of fire and ice.

This amazingly preserved Doric temple was abandoned before it was ever completed.

A Chinese mining company has created the world's first cloned village in this perfect recreation of an Austrian town.

This massive neon wheel is the only one of its kind to be built over a bridge.

The largest statue in the world towers at 420 feet high atop another 66 feet of pedestal.

This terrifying glass bridge on the side of a mountain cracks as you step on it.

A lush desert oasis in the shape of a narrow crescent.

Enormous burial mounds of ancient emperors.

China's very own Atlantis is an ornate dynastic city resting at the bottom of a lake.

Beijing's World Park offers the excitement of international sites without the travel.

Discovered after draining a local pond, these ancient man-made caves are still a complete mystery.

Jurassic theme park in the small town of Erlian.