The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

Traditional 11th-century outdoor tannery.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

An informal walk of fame in front of a Hollywood office building remembers a comedic great and his associates.

A "haunted" landmark on the coast of Southern California.

The sun acts as a key that only fits this giant keyhole twice a year.

A glittering South Asian anomaly in a wealthy Los Angeles suburb.

A giant donut stands as a popular symbol of Los Angeles iconography.

A Spanish artist builds his own castle.

The final resting place of the great navigator, or maybe his brother.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

Formerly a lovely white sand beach this Hawaiian stretch is now a trap for countless tons of trash.

This black shoreline is made up of exploded lava particles.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

You don't want to get caught in this trap--or do you?

A Swedenborgian glass church surrounded by redwoods sits perched atop a massive landslide area.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

A historic fort commemorating the United States' naval history.

America's most famous piece of self-built architecture.

A Looff creation in Santa Monica best described as “a California-Byzantine-Moorish-style fantasy.”

A hospital closed seemingly in the middle of operations, leaving behind fodder for horror films and ghost hunters.