The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

The origins of midtown Manhattan's anachronistic wooden farmhouse remain a mystery.

The first American department store, and home to the largest operating musical instrument in the world.

The tiniest little stage in New York.

Mysterious 500-year-old tapestries depict a unicorn hunt.

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

Lie in a hammock where George Washington stood.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

The man who first patented the Ouija board rests in peace beneath a headstone that playfully reflects that achievement.

Peek through the gates at this oasis from the city, full of Old English charm.

Test your business savvy and play the market for cocktails at this stock exchange-inspired watering hole.

On the top floor of an upscale department store stands a lavish restaurant housed in a replica of a luxury French dining car.

A huge resale shop for the cast-offs of the film & television industry.

A Manhattan Episcopal church with an eerie underground crypt.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.