The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

These 18th century gardens tell a rocky story of the son of Odysseus.

This natural crater along the coast of Jersey may take its name from the devil statues who have watched over it.

The view from this giant Stone Age toad is unexpectedly beautiful.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

A meditative space out of a fantasy story.

A charming Spanish village sits atop this natural limestone overpass.

This natural sea arch highlights Ireland's rugged coastal beauty.

In the middle of a suburban Denver neighborhood is a cave that once provided solace for a prominent Ute chief and his family.

Rare pigmented engravings cover the walls of this Stone Age shelter.

Bizarre dirt trail winds a narrow path above the tree line.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

Inside the Šomoška National Nature Reserve exists a unique rock formation rarely seen in the world.

The ridged layers that make up this river canyon represent Earth's geological history.

Over thousands of years, this slot canyon was carved out of the bed of an ancient lake.

A room filled with frescos that make it seem like the walls are crumbling down while giants die in despair.

Dozens of large-scale, creative, evocative curios from prominent artists dot the calm outdoor space around this major museum.

This five-foot-tall bronze bird is a memorial to a species that was hunted out of existence.

This museum in the tower of the oldest church in Gdańsk, is home to centuries-old time-keeping devices and the world's first pulsar clock.

This ramshackle ghost town is comprised of mining-era buildings collected from around the region.

An unexpected curiosity cabinet hidden within a department store in the Japan Post tower.

"Polynesia on the Plains."

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.