The video game-themed street art first popped up in the French city.

This legendary urban waterfall creates a dazzling display of rainbows.

This hidden bridge is where local children leave gifts and messages for the island's fay folk.

This small town's local tradition is to create the world's tallest ice pillar.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

Founded by a high school teacher, this poetry magazine became a center for all things literary.

After visiting hours, this picturesque waterfall is essentially turned "off" to be used for hydroelectric power.

A trough of 700 strange bronze faces runs through a narrow alley in Ljubljana's old town.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

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

This vertical pinnacle in China was the inspiration for the floating mountains in the movie “Avatar.”

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

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

Climb down into the largest sinkhole in Qatar.

Raging waters have created a strange geological site that looks like something off of a progressive rock album cover.

Romania's "Red Ravine" is a little-known natural wonder that bears a resemblance to the Grand Canyon.

After millennia of erosion by sand and churning water this Brazilian valley now looks like a lunar fantasy.

A massive natural rock arch gives the Tuscan mountain its own window to the sky.

A long, winding trek rewards you with a gorge so captivating it inspired a painting in the Tate.

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

This extraordinary geological oddity resembles human-made pavement.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.