This artificial cave looks like something out of a fairytale.

Macabre astrological automaton clock dating to the late 1400s.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Countless grotesque faces stare out from this eerie Prague art wall.

A Jenga-style cylindrical tower of books that appears to go on forever.

Two stunning 17th-century libraries and a cabinet of curiosities.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Legend has it the lovelorn tears of a princess and a shepherd boy formed the blue and green twin lakes in the Azores archipelago.

This enigmatic Roman tower lurks just outside Belmonte.

These narrow stone granaries have been used to store and dry out grain for hundreds of years.

This chapel is the site of a yearly pilgrimage that originated during the Middle Ages.

A fortress off the West coast of Portugal that dates back to 1502.

The medieval town's star-shaped walls are geometrically dazzling, though not entirely impenetrable.

This castle has links to Portugal’s founding and struggles for independence.

An honorary saint of the people, Maria Adelaide became an incorrupt corpse, the clothes intact, exhaling “a strong scent of roses.”

An abandoned tuberculosis hospital said to be haunted by the patients who died within its walls.

A lush oasis full of vibrant plants and striking geometric displays.

The extravagance of Portugal’s "Pink Palace" resulted in a noble title being awarded to its owner.

A windswept necropolis carved into the rocks overlooks the "most Portuguese town in Portugal."

A cluster of granite granaries perched on stilts.

This giant sculpture made of trash is a critique of society's wastefulness.

This star-shaped military outpost is now simply trying to protect itself from neglect.

One of the largest Roman settlements in Portugal.