This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

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

This legendary city has been a tourist attraction for centuries.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Legends surround an ancient tree trunk riddled with nails for good luck.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

1513 Turkish world map, full of European state secrets and snarky commentary.

Learn to drink tea like an Estonian at this museum.

A medieval setting reimagined into a unique art alley.

This 13th century Gothic brick castle is the largest in the world by surface area.

Naturally formed rock city in Poland.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

A Baroque mansion with ties to legendary magicians and alchemists.

A cheeky reminder about the value of art dangles above one of Olomouc's busiest streets.

An unusual bronze bus shelter is actually an art installation commenting on the city's history with the Nazi party.

Tiny communists hammer away on the Olomouc Astronomical Clock.

Tall columns of volcanic basalt make up this improbable-seeming rock formation.

The sanctuary holds what was once believed to be the saint's incorruptible tongue.

An ornate plague column – built to celebrate life – claimed the lives of numerous artisans during its construction.

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

One of the famous Czech artist's lesser-known Prague installations appears to be a glowing fetus affixed to a drainpipe.

This automated sculpture of two men peeing will spell out text messages with their micturition.