Stunning Roman aqueduct used for 1900 years and still standing.

This Roman arena once played host to bloody gladiatorial battles.

This 47-story "M" needed 20 years to be completed

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

This colorful statue welcomes visitors to a Barcelona park.

An early 20th-century bullring converted into a modern shopping center.

This clifftop arch is a natural stunner.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

The only surviving choragic monument is a trophy awarded in 334 BC for the winning dramatic chorus.

This striking sculpture of Icarus honors Greece's fallen flyers.

A sharp sculpture made of thousands of pieces of jagged glass.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Traditional 11th-century outdoor tannery.

The other side is actually green.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

Striking occult iconography on a medieval German church.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This historic stone bridge has an entire neighborhood clinging to its sides.

The fairy tale castle of the "fairy-tale king."

This bridge made famous in a novel and on-screen wasn't actually built over the river Kwai.

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