A 30-acre garden inspired by the principles of modern physics.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

A tongue-in-cheek arcade where the games are based on everyday life.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

These fantastically named natural pools look like something out of a Scottish myth.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

Quite possibly the oldest love poem known to humankind.

The eclectic home of a leading Turkish architect is a gorgeous piece of eye candy.

A sixth-century Byzantine cistern hidden below a modern carpet store.

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.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

A meow-velous tribute to a beloved street cat, made famous on the internet.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

A statue of an astronomer gazes at the sky as a tribute to Caroline Herschel.

A grumpy old water goblin guarding an old mill on the Devil’s Stream in Prague.

A Baroque mansion with ties to legendary magicians and alchemists.

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

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

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

Countless grotesque faces stare out from this eerie Prague art wall.

One of the oldest structures in Helsinki is this burrow grave that dates back to the Bronze Age.