This ancient stone bridge dates back to the early Middle Ages.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

Time stands still at this serene burial ground in the center of Budapest.

The largest statue of this convex, homogeneous object with just one stable and one unstable equilibrium point.

The Grand Mall in Varna hosts one of the biggest collections of Soviet-era paraphernalia in Bulgaria.

This once-grandiose behemoth of a monument from the socialist era now sits quiet and closed up.

Massive, unfinished broadcasting station stands as a monument to the fall of communism.

The site of many battles and tragedies, including the 40 maidens who leapt into the sea.

Twisted buildings adorn the banks of the Rhine river.

This futuristic German television spire is actually the world's largest digital clock.

This "floating railway" is one of the world's oldest monorail systems.

Amsterdam's former hotspot for public executions and dissections.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

A little sculpture with a large wardrobe.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

Europe’s oldest natural human mummy.

Bell tower juts out from a village buried under a lake.

This massive statue is the personification of Bavaria and the first colossal statue of the modern period composed of bronze.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

A fearsome dragon clings to a corner of Munich's city hall.

One of the most easily accessible examples of the rare 1960s UFO houses.

Hitler's bleak vision of relaxation still stands as a mostly abandoned 10,000-room resort complex.