This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

This region of the Perugia municipality has an unforgettable name.

Fountain where visitors can earn a license to be mad.

Five candy-colored villages on the Italian Riviera.

A lover's walk between hilltop towns, decorated with graffiti love notes.

Eighty million natural history specimens call this gargantuan museum home.

Catacombs turned marketplace.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

One part local history, 99 parts gruesome haunted house.

An unusual round church in London with a Templar past.

Hidden beneath the streets of London is a secret subway that only carried mail.

Rebuilt remains of a temple to Roman god Mithras.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

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.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

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

This sprawling Jewish cemetery is one of the largest in Europe.

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

A restaurant and observation deck built in a unique broadcasting antenna.

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

A surreal museum of extraordinary industrial objects.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

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