Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.

An exquisite grouping of structures made from 10 tons of invasive saplings.

A collaboration of art and ornithology mourns the calls of Sydney's lost birds.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

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

The highest point in Maine is a grand gift to the state citizens that also happens to be one end of the Appalachian Trail.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

The last occupied troglodyte dwellings in England weren't abandoned until the 1960s.

A series of modernist treehouse hotel rooms grace the outskirts of an Arctic forest.

Mysterious spherical rocks in the semi-desert of western Kazakhstan.

Highly spherical boulders on the shores of New Zealand.

The mysterious round rocks of Schooner Gulch.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

A vast, otherworldly collection of Buddhist stupas.

This unique temple complex remains off the typical tourist trail.

Rare recess caves fill this unbelievably beautiful Ohio park.

This beautiful grotto is one of those places where you can't believe you're just outside Austin.

A popular swimming hole that hides one of America's most deadly diving spots.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

Walk in the footsteps of the gods and straddle two tectonic plates.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.