A winding, blood-red tunnel of hardened lava navigable by foot.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

A fairytale-like medieval church perched atop a rocky cliff on Italy's "Coast of the Gods."

One of the world's oldest universities houses an incredible collection of anatomical models, mummified body parts, and human bones.

This Seattle museum displays the history of the telephone through an impressive collection of telecom equipment.

A giant Troll lurks under one of Seattle's oldest bridges.

A 100-year-old purveyor of curiosities, curios, and kitsch featuring mummies, shrunken heads, and a Fiji Mermaid.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Southern Italy's spinning top village.

Dramatic sea stacks adorn the coast of this small village on the Adriatic coast.

More tin toys than you can shake a clapping monkey at.

The legendary birthplace of the Japanese maneki-neko is dotted with hundreds of lucky beckoning cats.

Two awe-inspiring globes from the reign of the Sun King hang from the ceiling of France's national library.

A rambling museum which honors the beauty in everyday objects.

A cheeky architectural easter egg.

Graffiti covers the walls of a room where university students through the centuries have waited nervously to defend their theses.

The place to be if you love vintage Swedish cars.

Architect Le Corbusier built his friend a cubist house to match his impressive collection of cubist art.

Hidden away in a modern library are the remains of one of the 18th century's most celebrated wunderkammers.

The first green space constructed on an elevated viaduct.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

Stroll through retro Paris while shopping for old postcards and discarded doll heads.

One of the oldest medical collections in Europe focusing on rare surgical instruments.