Roman ruins top white travertine terraces formed by ancient hot springs.

Moss and stone turn this waterfall into an otherworldly liquid veil.

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

Museum dedicated to awful artwork.

A century-old network of freight tunnels underneath the city's historic business district.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

Stay in a room with a view... of the bottom of the ocean.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

The world of the ancient Celtic civilization explained through a bewitching 11 acre garden.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

This 16th-century monastery has been turned into a surrealist architecture compound.

The largest greenhouse in the world is home to over one million types of plants.

A technicolor place of worship for Elevationists.

A historic neighborhood church is reborn as a psychedelic arts collective.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

Walk through Czech history in Prague's largest graveyard.

A once grand hotel is being retaken by the wilderness it once capitalized on.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

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

Despite the ever pressing encroachment of urban sprawl this grand New Orleans manse still stands.