This abandoned Slovenian military barracks has become a punky-political art squat.

This 13th century Gothic brick castle is the largest in the world by surface area.

The silly symbol for an underground protest group is now scattered around the city.

Communism's topsy-turvy effect on Poland has been brought to life in this wacky tourist trap.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

A student driver's nightmare.

The London pub overlooks where the Mayflower was moored before setting sail for the New World.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

This hidden green space is the city's second largest conservatory.

Famously misunderstood wonder of the ancient world

This South London cemetery holds the remains of more than 15,000 people.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

Eighty million natural history specimens call this gargantuan museum home.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

A kaleidoscopic warehouse-maze of handmade neon signs.

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

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.