A graceful natural rock formation stands astride the point where the Gulf of California meets the Pacific Ocean.

Tucked between a side street and a theater, this arch once led to a prestigious riding school, and now opens to a courtyard and community garden.

The fifth-longest natural arch in the world, and the longest outside China.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

Unlike most arches, this geological oddity formed in a volcanic dike.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

This bird-shaped rock formation defies gravity, time, and classification.

This magnificent arch is all that remains of a former smelt mill.

This clifftop arch is a natural stunner.

A triumphal steel arch on the side of a German mountain.

When new viceroys were elected, they passed through this arch to cement the title.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

The hallucinogenic center of the ancient world.

The world's longest known cave system.

These otherworldly limestone formations jut out from the Kansas prairie.

This narrow coastline trail through the dense Kauai wilderness is among the most beautiful and dangerous in the world.

Peak named for an old man who liked to run in the nude.

A large stone map of Arkansas awaits visitors to its highest point.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Fine dining 20 feet below the surface in the Indian Ocean.

Hitch a boat ride to dine on stilts while watching wildlife.

A historic shipbuilding town is home to a sail-through fish-and-chips shop.

An underwater restaurant, surrounded by a coral reef.

This pirate-broadcasting-tower-turned-restaurant played a rebellious role in the history of Dutch television.