Gladiators once walked this ancient, subterranean passage.

A former royal garden with lush surroundings in the heart of the city.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

An ancient octagonal weather station named for the eight Greek gods of wind.

This abandoned Greek island was the last active leper colony in Europe.

This famous archeological mystery may be an ancient example of movable type.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

A small island with shimmering pink sands, home to loggerhead turtles and rare plants.

This stone tower was built to protect Crete from incoming pirates.

A mocking tribute to the past and modern leadership of Prague.

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

Macabre astrological automaton clock dating to the late 1400s.

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

The oldest garden in Prague, once part of an medieval orchard.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

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

A peculiar clock commemorates a historic victory won by ringing the noonday bell an hour early.

This Croatian fairytale castle is slowly falling apart thanks to years of neglect.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Piran’s oldest square is laden with history and a beautiful 18th-century reservoir.

This lush, scenic spot was carved by the turquoise waters of the Radovna.

Inspired by the Rialto Bridge in Venice, these three clustered bridges were just one part of a Slovenian architect’s grand vision.