Opulent downtown movie theater now houses cars as an indoor parking garage.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

This sprawling bookstore spans four floors and has more than a million books in stock.

This secret collection of the strange and occult was rediscovered in a forgotten room of an old house.

Ample proof that watery ends make for well-preserved, millenia-old mummies.

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

At one of Berlin’s oldest churches, visitors can place mosaic tiles to help restore a medieval mural.

This 8th-century Bavarian monastery is home to an exquisite Baroque-era library.

A fearsome dragon clings to a corner of Munich's city hall.

The footprint of a frustrated devil in Munich's Cathedral.

This German bone house contains the remains of some 20,000 souls.

A wunderkammer of mysterious objects and stories.

A slice of central Asia in the middle of Berlin.

An eerie, derelict amusement park in Berlin.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

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

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

This speakeasy continues the Prohibition-era legacy of Harlem's jazzy Swing Street.

This historic building housed the surviving crew members of the Titanic, who were left destitute after the wreck.

Finally, you don't have to be a pious Swedish seaman to relax like one.

A charming "tea atelier" hidden away in Greenpoint, Brooklyn.

Though its celestial ceiling is impressive, the true star is the vast collection of French books.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

The body of an unidentified woman, visible through a glass coffin, was discovered by accident.