These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

The best Tiki bar in Las Vegas.

An old world fairytale-land with over 350 fairy folk figurines hidden amongst 800 year old cedars.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This tangled English forest looks like something right out of a fairytale.

Catacombs turned marketplace.

Rebuilt remains of a temple to Roman god Mithras.

The hidden lair of an alchemist rediscovered in a 2002 flood.

A Jenga-style cylindrical tower of books that appears to go on forever.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

The world's largest collection of witchcraft regalia.

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

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

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Stroll through a wonderland of stupendous moss-covered trees.

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

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

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

These fantastically named natural pools look like something out of a Scottish myth.

A kaleidoscopic warehouse-maze of handmade neon signs.

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