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

Each year melting snow turns these Austrian hiking trails into scuba zones.

Go surfing on this urban wave, "hacked" by local surfers.

A serious museum dedicated to two German comedians.

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

It's always summer at the beach inside this former airship hangar.

This German version of Universal Studios holds a vault of treasures from the NeverEnding Story.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

The fully functional, submerged Vanuatu Post Office is definitely one of a kind.

The world's only museum devoted to the wonders of fluorescence.

An elevator into the Baltic Sea.

This former steel and coal plant is now a neon-lit industrial fantasia.

Twisted buildings adorn the banks of the Rhine river.

This collection of solar timekeepers includes the world's first digital sundial.

A varied collection of brains in alcohol.

Somewhere there is a giant who can no longer poop, but now travelers can stay inside his anus.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

Kentucky, Tennessee, and Virginia meet at this point in the Cumberland Gap.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.

No need to strap in for a "ride" on this walkable roller coaster.

Go inside a revolutionary, cage-less zoo where 70 species of monkeys roam free alongside their human visitors.

The world's biggest pet store.