In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A spectacular cave and a beguiling lake.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

Enormous lake at the bottom of a unique cave system.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

Two stunning 17th-century libraries and a cabinet of curiosities.

Northern Ireland's Brobdingnagian stepping stones.

A seemingly endless landscape of pure salt stretches far across Bolivia.

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

Stunning wetlands ablaze with pink lotus flowers.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

An enormous, inside-out glass globe built in 1935.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

Macabre astrological automaton clock dating to the late 1400s.

The world's largest collection of witchcraft regalia.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

A 16th-century horror show built in a lovely Italian garden.

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.