Bacteria and algae give the salty water its bubblegum hue.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

A stately palace has been converted into the world's largest cannabis museum.

A lush indoor jungle fills this bustling Madrid transportation hub.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

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

Three bridges and one giant canyon make up this fantastic Spanish settlement.

This cemetery features modernist statues as strange as its name.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

A beautiful but toxic fountain of mercury.

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

This semi-secret storybook hedge maze is also the oldest garden in the city.

Palatial mansion estate used in films including "Flowers in the Attic" and "The Witches of Eastwick."

An underwater statue of Christ blesses the coral reefs off Key Largo.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

Ghost stories surrounded this “castle,” the only structure from a huge mansion that was never built.

This secluded walking trail is a hidden gem of a Pittsburgh park.

Five acres of divinely inspired folk art.

A wedding chapel, vintage clothing shop, and bar all under one roof.

An unusual art exhibition in a suburban yard is designed to awaken the souls of those flowing by.

Inside an old airplane hangar, friends and strangers alike play on a massive trampoline.

The world's largest occupied bat houses hold hundreds of thousands of flying mammals.