This sawtooth mountain range still bears the strangely lovely marks of its history as a medieval quarry.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

An ancient stone fortress considered by many to be the eighth wonder of the world.

A fairytale island floats in the middle of Italy's little-known Lake Orta.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

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

These layered sandstone mountains in China look like they are made of pressed crayons.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

This spectacular bridge supported by two gigantic hands looks like something out of a fantasy universe.

The convergence of two currents makes this a surprisingly pleasant getaway in the Arctic Circle.

Three columns of volcanic rock shoot out of the ocean.

An unfinished rail tunnel that has since been used to house cheese and bats.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

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

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

An icy lake tucked among jaw-dropping alpine panoramas.

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

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

The steepest classic funicular in the world glides along a dizzying incline.

The oldest (maybe) swimming pool in Iceland is a stunning oasis built into the side of a lush hill.

This one-time health resort was used by aristocrats around the world.

This "preacher's pulpit" once used for pagan ritual, is home to a new, and dangerous ritual.

A trio of hidden hot tubs takes advantage of Iceland's natural geothermal vents.