An existential riddle in the world's largest ancient castle.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

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

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

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

A church of bones, decorated with 40,000 human skeletons.

Macabre astrological automaton clock dating to the late 1400s.

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

Microscopic scenes; some call it novelty, some call it art.

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

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

One of the two original gateways into the Kasbah, this gateway is a nesting site for storks.

Sleepy fishing port not included on many maps.

Mosaics, storks, and brothels—this ancient city has it all.

The courtyard of this small Marinid madrasa is a dazzling example of intricate Islamic architecture.

Along the most northwestern point in Africa is an ancient cave surrounded by legends.

One of the most spectacular canyons in the world.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

The ancient latrines of the Greeks, in all their public glory.