Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

Three prestigious academic collections come together to create a world-class natural history museum.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

Try not to get slimed in Tribeca.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

A stealthy Apache hideaway that became the haunting site of a mass grave.

Once a speakeasy operated by Al Capone, this Milwaukee cigar bar is now a haven for ghost hunters.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

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

A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.

The mortal remains of an estimated 70,000 people lie in the basement of a monastery in Lima, Peru.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

One of Ireland's most infamous prisons for rebels including men, women and children.

This award-winning men's bathroom was just too beautiful to not allow women to see.

A market for witches is hidden within a train station.

This tin chapel was built by POW's during World War II and is painted to look like something much more grand.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

The oldest continual pilgrimage site in Britain was supposedly created by a gruesome beheading.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

The history of whiskey and all of its boozy glory, from Colonial days to modern American cocktail culture.

The longest navigable underground river in the United States is home to countless blind and albino animals.

This Victorian-era public house has set the standard for pub-style elegance for over a hundred years.