This 11th-century castle sits so low you can't see it behind the surrounding buildings.

For over 100 years the most important physicists in the world have autographed this university wall.

A lecture hall sink once used by Einstein and other noted physicists is now regarded as a strange science relic.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

Science meets wall art to highlight the beauty of famous mathematical equations.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

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

What looks like a suicide in progress is actually a statue of Sigmund Freud.

This spooky statue sits outside a famous Prague theater.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

Steadily reminding Czechia of its past.

A rare example of World War I trenches from the British front.

A moving memorial to the fallen and missing from WWI trenches.

This memorial museum chronicles the apocalyptic destruction of the First World War.

The bronzed skull of a beheaded traitor was affixed to the city gate in the 17th century.

You can spot this teeny tiny stained-glass window from the Bonifacius bridge.

Christ's blood allegedly preserved in a Belgian town.

Meet the bronze beloved pet to a family of famous peeing statues.

A little sculpture with a large wardrobe.

Belgium’s famous peeing statue has worn many hats (and coats, and pants), which are on display at this small museum.

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

Brussels' favorite peeing boy has a sister.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

A replica of a 17th-century map of the stars stands in the courtyard of a Belgian university.