Amalfi's pre-industrial history is slowly being engulfed by the lush vegetation of the Ferriere Valley.

A limestone grotto where daylight filters in from below and turns the water a beautiful turquoise. Also home to a small underwater nativity scene.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Hikers can still stroll beneath the long conveyer of this abandoned mining facility hidden in a West Virginia river gorge.

These craggy limestone outcrops offer a glimpse at a unique piece of Florida geology.

Hidden in the plaza next to a pizza shop is an amazing little oddities shop.

Where serial killer Aileen Wuornos drank her last beer.

One of the largest Native American shell middens stands 30 feet tall.

A secret, rocky playground hidden amongst the plain white beaches of the Florida coast.

One of seven Jewish catacombs in Rome and one of only two open to the public.

An abandoned 17th-century baroque hunting lodge with a wonderfully strange architectural plan.