Despite its grandiose name, this enigmatic first-century void under the town is no cave, and it's possibly not a palace either.

This landmark is a central figure in the Nez Perce origin story.

This medieval sanctuary's tree-framed door looks like a portal to a mythical realm.

This lone tree and dramatic sandstone outcropping are so beloved by Michiganders they can be found on one of the state’s coins.

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

These ornate arches show how the course of the River Thames has changed.

The little-known second castle that William the Conqueror built in York.

A gruesome and mysterious ancient sculpture of a pagan deity from the Roman occupation of Celtic Britain.

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

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

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.

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.

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

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

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

Rare recess caves fill this unbelievably beautiful Ohio park.

Known as one of the most climbed mountains in the world, this barren peak is permanently bald thanks to an anti-wolf fire.

Scotland still bears an enormous scar of its Roman past.

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

Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."