The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

A 12th-century fortress containing some of Berlin's oldest buildings.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A wunderkammer of mysterious objects and stories.

A collection of abandoned typographic signs from Berlin and beyond.

The most visited, and possibly most controversial, museum in Germany.

Started as a kitchen garden, now the second largest botanical garden in the world.

A slice of central Asia in the middle of Berlin.

More than a million titles fill the labyrinthine shelves of this prestigious private library.

The canine-themed book collection claims to be Europe's largest dog library.

Historic cuisine meets fine dining in a hotel-restaurant overlooking Hyde Park.

The bar where "The Great Train Robbery" was planned was once a nexus of high society and low morals.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

The sumptuous ceiling was one of the last things Charles I saw before his execution.

An unusual round church in London with a Templar past.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

Eighty million natural history specimens call this gargantuan museum home.

A castle in the Scottish Highlands has been continuously inhabited since the 1300s.

A beautiful Greco-Roman structure houses a well once believed to have healing powers.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Legend says a witch conjured the world's third largest whirlpool to protect Scotland from a nasty pirate.