The final resting place to 300 Victorian-era pets hides inside the city park.

Moorish signal station on a stratgic rocky outcrop.

Abandoned Nazi train station turned underground astroparticle laboratory.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

A once-secret library of Freemason history in Catalonia.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

This cafe offers a curated collection of treats and tipples made by monks and nuns.

The studio of Catalonia's most famous theatrical designer remains exactly as he left it.

Commonly acknowledged as the only public monument to the Devil himself.

Turntable anonymously received orphans, alms, and groceries.

Bacteria and algae give the salty water its bubblegum hue.

A beautiful but toxic fountain of mercury.

This abandoned stepwell is one of the largest, deepest, and certainly one of the creepiest in India.

A startling, centuries-old subterranean marvel hides in plain sight.

Elaborate stone houses constructed from the ruins of war.

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

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

From the Difference Engine to the Cray-1, all under one roof.