A temple to modernity, tucked away amid Barcelona's more well known museums.

Come to this Polish museum to take a good, clean look at filth.

From morgue to urn, watch the whole process at this unusual educational attraction.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

This otherwise innocuous bodega was once the headquarters of the most feared assassin's guild in American history.

Statue commemorating the use of ether in anesthesia.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

Nightmarish example of the unintended consequences of weapons testing.

Museum deep in the catacombs of St. Michael the Archangel Church is explored by touch, sound, and smell.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

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

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

Long abandoned underground complex to keep royals safe from a nuclear war that never came.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

One woman's decades-long obsession with the "La Fée Verte."

This French anatomy museum greets guests with a skinless man, mid-shovel.

The largest and most famous wax anatomical collection anywhere in the world.

The Japanese mayo factory famous for its cute mascot.

This tiny museum kept in a B&B laundry room holds the death mask of notorious bank robber Pretty Boy Floyd.

The house where the famed outlaw was shot by a dirty coward is now a museum to the criminal's legacy.

A 120-year-old legend concerning an empty circular patch in the North Carolina woods.

A museum and shop on Bourbon Street located in the former home of the second Voodoo Queen of New Orleans.

“Invented in Key West, Perfected in Brooklyn."