Mutant vegetables, transgenic mosquitos, and atomic rodents span the walls of this one-of-a-kind museum.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

The mummified relic of St. Antoninus.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

In the bowels of a 19th-century brewery lurks a fine-dining restaurant offering an array of themed feasts.

This expansive bridge in the Canadian wilderness was originally just built for friends.

A museum dedicated to the strange and extravagant costumes and memorabilia of the mummers, a tradition older than Philadelphia itself.

A unique spiral staircase that doesn't quite make it up to the top floor.

A museum designed by and dedicated to P.T. Barnum in the town where he is buried.

This contemporary art museum is filled with other, smaller museums, which feature work from artists primarily in the Pacific Northwest.

The tallest outdoor elevator in Europe rockets passengers on a dizzyingly precarious ride to the top of a mountain.

A 100-year-old purveyor of curiosities, curios, and kitsch featuring mummies, shrunken heads, and a Fiji Mermaid.

This stucco building in North Africa was the first American-owned property on foreign soil.

This monastery set over a holy cave contains the oldest known painting of Saint Francis of Assisi.

Wander through the Corridor of Wonders in these stunning limestone caverns.

Strange physical sensations and optical contradictions keep visitors coming back for more.

This public space is speckled with the eerie remnants of a defunct amusement park.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

This pebble beach is so beautiful that taking its rocks is against the law.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

The attic of a four-century-old canal house hides a clandestine church.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

Where royalty waits in the height of luxury.