One of the world's largest salt caves is filled with fragile salt sculptures, salt rivers, and huge salt megadomes.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

A remote desert lookout offers unparalleled views of the California badlands for those who brave the trek.

This precariously balanced boulder is said to be a hunk of stolen butter dropped by the gods.

Picnic on the seashore in the footsteps of ancient kings, protected by giant mythical cat beasts.

A cemetery with goat-horn bedecked gravestones.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

An Icelandic island full of diving birds and legend.

Cathedral carved out of salt, located a mile below the earth's surface.

This picturesque mansion has gone from opulent ruin to nature museum.

Hidden amid the tropical forest in the Caribbean Sea are the decaying ruins of the Cocaine King's luxurious island party home.

A little known Colombian theme park of giant curiosities.

An explosion of natural color known as "the river that ran away from paradise."

Unparalleled stargazing, one of Colombia's best observatories, and a swimming pool can all be found in the middle of this ancient tropical forest.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

An entire city block built completely out of petrified wood.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

The remnants of an early American attempt at missile defense.

These former Cold War launch sites have been preserved for tourists to see where the button might have been pushed.

Centuries before the modern seismograph, Armenian monks measured quakes with this tilting pillar.

This scalding hot river was thought to be a myth until one geoscientist made it his quest to study the mystical waters.

One of the world's tallest waterfalls wasn't revealed to the world at large until 2006.

This wondrous waterfall rushing down a green-covered mountain wasn't discovered until 2010.