A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

This bridge was constructed from the rubble of the infamous Bastille.

Macabre astrological automaton clock dating to the late 1400s.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

The world's largest wooden structure.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Once the home of a hermetic monk, this cave now houses a small church.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

France's most famous cemetery, with some of its most curious tombs.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

A unique Holocaust memorial tells the personal stories of the Jewish residents exiled from greater Berlin.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

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

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

An old department store turned Nazi prison turned artist commune.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

This conical hill was built as a testing ground for an engineer known as the Glider King.

Cold war icon and onetime "hole" in the iron curtain.

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

A fascinating insight into daily life in the Eastern Bloc.