Abandoned Nazi train station turned underground astroparticle laboratory.

An open-air sewer system that was covered piece-by-piece over 300 years.

Most prolific publishing house in the 1600s open to the public.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

This castle was established by the 4th Duke of Montrose and is connected to the Buchanan Clan.

Largest island in the Baltic Sea experiences such idyllic weather that roses bloom in the middle of December.

20-foot tall lamp mumbles Swedish to celebrate the holidays.

Rumored to be the famed pirate's lookout tower, this historic stone structure is now just watching for tourists.

Home to items never before seen by the public.

This picturesque mansion has gone from opulent ruin to nature museum.

One man's homage to the sun continues to grow like a glass fractal.

A war-torn Olympic relic is being overtaken by graffiti and nature.

Where Agatha Christie mysteriously disappeared in 1926.

A surrealist timepiece by the artist of melting clocks.

A fortified city, home to a remaining population of five families

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

A site of pagan worship which still attracts people looking for fairies.

Nondescript elevator doors open to reveal a stunning, surreal world.

This Arabesque Italian castle was built with a primitive, if ingenious, air-conditioning system.

This inanimate goat created by the "welding nun" has been helping to clean up the city of Spokane for more than 40 years.

A memorial to the victims of Argentina's "Dirty War."

One of the ghostly stops along Route 66.

This half-finished "city of toys" was almost Italy's own Las Vegas.

Come for the speed, leave in love with the desert.