The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

A Spanish town built into the cliffs.

A white Buddhist temple with a golden restroom.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

A corkscrew-shaped barn in Ireland.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

An underwater restaurant, surrounded by a coral reef.

A total of 999 stairs lead visitors through a massive hole in a mountain known as the Gateway to Heaven.

The heads of two giant mythological water horses honor Scotland's horselord past.

A bronze statue dating back as far as 1252, still has remnants of gold on its right cheek from ancient gilding.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.

These ominous lava formations were said to be an entrance to the netherworld so of course they inspired a famous metal band.

A dangling church built over a Colombian gorge.

The palace of the King of Kings, burned by Alexander the Great.

A stunning silver lining to global warming's gloomy cloud.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

These sub-farmland caves are home to a majestic stalactite known as the "Crystal King."

A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.

A naturally beautiful, seemingly bottomless deep blue spring.

A remote candy-striped mountain in the Peruvian Andes straight out of the pages of Dr. Seuss.

Each year melting snow turns these Austrian hiking trails into scuba zones.

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