The translucent turquoise hue of these natural swimming pools comes from a high concentration of minerals.

The same water that fills a luxury resort’s pools feeds these free hot springs in the rainforest.

In Costa Rica's cloud forest, the roots of a woody ficus create a botanical bridge.

Disused penal colony features prisoner artwork, some sketched in human blood.

In this desolate valley resides a gorgeous set of rocks sporting a technicolor design.

Vast stretch of tide-pools with a unique Moroccan charm.

The former home of Dutch anthropologist Bert Flint now houses a collection of Berber art and artifacts.

Founded as a refugee camp, now a popular tourist spot.

Morocco’s modern capital was once a haven for Barbary pirates, who went so far as to establish a republic of their own.

This restaurant sits within the walls of an 18th-century fortification that once defended the city’s old quarter.

Italian horror legend Dario Argento’s own shop hides a sinister museum-dungeon in the basement.

A ghostly mansion in the middle of downtown Tunis.

Legend holds that the Ancient Greek goddess of love once bathed in the waters of this grotto.

This former quarry is now a picturesque gorge that hides a sunken lake.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

700 iron sculptures crammed into a Mediterranean park.

Explore an eerie, abandoned medieval citadel.

One of the greatest maze designer’s greatest mazes.

This building’s ghostly exterior reflects its former lives as a prison, school, and funeral home.

Nicknamed the "Museum of Horrors," this French anatomical collection has been fascinating visitors for over a century.

This hidden garden boasts amazing views of Lyon.

An art world insider finds himself battling for his artistic home.

These hooded graves are the only of their kind in the United States.