A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The first declared National Monument in the United States.

The ghostly remains of an accidental sea.

Mountain of unimaginable riches that bankrolled the Spanish Empire, complete with its own underworld god.

On the outskirts of a desert trading village high on the Andean plain, steel giants have been destroyed by salt winds.

A seemingly endless landscape of pure salt stretches far across Bolivia.

The world's highest and most dangerous infinity pool lies at the precipice of Victoria Falls.

Medicinal spa created with the discharge from a geothermal energy plant.

The first museum in the world devoted to sexual gadgetry.

Macabre astrological automaton clock dating to the late 1400s.

A gruesome memorial for those lost in this area during the Khmer Rouge genocide.

A battle between nature and architecture in the Cambodian jungle.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

If you’ve ever seen a picture of Machu Picchu, then you’ve seen a picture of Huayna Picchu—you just didn’t realize it.

This was once the center of the Birdman cult, and is now a World Heritage Site.

The world's most remote airport.

The largest stone moai on Rapa Nui.

Dramatic river bend surrounds a natural red-rocked pedestal.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Rippling sand dunes frozen in the Arizona rock.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

A painting in the historic Cathedral Basilica depicts Jesus and his disciples dining on a traditional Peruvian menu.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.