A museum dedicated to the history and exploration of both popular music and science fiction.

A giant Troll lurks under one of Seattle's oldest bridges.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

"There's nothing there," and other lies the KGB told us.

Where commuters walk through remnants of an ancient Greek necropolis.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

This peaceful Sikh gurudwara serves around 50,000 free meals every day within its gilded walls.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

Tucked in the back of this amazing antique store is an important piece of medical history.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

From toys to kettles to scientific instruments, this German museum celebrates the beauty of 20th century design.

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

Art and a pun, all in one.

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

Pre-Nazi swastikas adorn the sculpted pachyderms flanking this brewhouse portal.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.