One of downtown Berlin's last reminders of its Communist past.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

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

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

Metro station with a claim to rock n' roll fame.

Berlin's beloved bear is immortalized at the Museum für Naturkunde.

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

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

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

A space dedicated to contemporary art and culture, co-chaired by fashion icon Miuccia Prada.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Commonly acknowledged as the only public monument to the Devil himself.

A once-luxurious, now abandoned hotel in the Italian Alps.

Banksy gives themself artistic license with this piece of London street art.

A flourishing garden with pigs, donkeys, goats, rabbits, guinea pigs, chickens, ducks, and sheep.

London's smallest police station is barely the size of a phone booth.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

The mountaintop inspiration for Umberto Eco's "The Name of the Rose."

An eccentric collection of antique items shares space with a prop-quality witchcraft museum.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

The world's largest wooden structure.