The ancient mosaics here are considered among the finest in the world, and serve as a stunning record of Greco-Roman daily life.

Monasteries on rock pillars, once accessible only by frayed ropes.

The hallucinogenic center of the ancient world.

An abandoned saucer-shaped monument in the Bulgarian mountains.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Museum dedicated to the terror regimes of Hungary.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

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

This one-time health resort was used by aristocrats around the world.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This man-made mound monument was built out of soil from all across the Polish empire.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

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

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

This cubist Vienna church building looks like some sort of alien stonehenge.

A grassy pyramid named after a French battle.

Once the local rulers had gone these enchanting ruins housed common folk in an almost real life fairy tale.

Brussels' favorite peeing boy has a sister.

A little sculpture with a large wardrobe.

Cozy basement bar sports an inventory of over 2,000 beers.

Climb inside an iron crystal magnified 165 billion times its normal size.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.