Pamukkale might just be the world’s most otherworldly place to take a bath. This terraced spot in southwestern Turkey might look snowy, but that’s the result of built-up minerals deposited by natural hot springs over the eons. It’s been a favored spa retreat for more than 2,000 years, and its name means “cotton castle” in Turkish.

It seems almost inevitable that a natural feature as unearthly as Devils Tower might be considered supernatural. Nearby Native American tribes hold it sacred, and aliens landed here in the 1977 film "Close Encounters of the Third Kind." Scientists aren’t sure how the monolith was formed, but they agree the rock came from within the Earth, not from another planet.

No wonder Irish legend holds that the Giant’s Causeway in Northern Ireland was constructed by a mythical warrior; it just doesn’t look like something nature would have created on its own. But that’s exactly what it is — a field of thousands and thousands of basalt columns formed by ancient volcanic activity. Follow in the giant’s footsteps with a trek down the causeway to the sea.

Western Egypt's White Desert gets its name from the chalk that whitewashes the place. Besides making the Sahara outpost look practically snowed under, the chalk stands tall in formations that have been eroded by sandstorms into fantastic shapes — mushrooms, spires, pinnacles and anvils.

Interesting rock formations are abundant in Abel Tasman National Park on New Zealand's South Island, but none is weirder than Split Apple Rock, rising from the water of Tasman Bay. The giant boulder has been broken in two pieces so cleanly that it’s almost as if a giant hit it with an ax.

If you were a rock and looking at a sedentary existence, wouldn’t you wish you could explore? Maybe that’s what’s going on with Death Valley's sliding stones, which leave trails behind them as they amble around the dry lake bed at Racetrack Playa when no one’s looking. How they move around is unknown — and the stones aren’t telling.

The island of Socotra, at the mouth of the Gulf of Aden, has been called the most alien-looking place on Earth. A third of its plants are found only here, and many of them look downright strange. The most bizarre of the bunch is the dragon’s blood tree, which looks like a big stalk of broccoli and has red blood — dark red resin, that is.

The island of Bohol is home to hundreds and hundreds of closely clustered limestone domes called the Chocolate Hills because of their carpet of grass, which turns brown in the dry season. Scientists aren’t sure how they formed, but hopefully it wasn’t due to a giant water buffalo that got a bad case of food poisoning, as one local legend holds.

Mono Lake, California

They say that truth is stranger than fiction — and you could argue just as strongly that Mother Nature comes up with much more bizarre stuff than we ever could. Here are just a few of Earth's weirder wonders.

Just getting to Mono Lake, near the Nevada border, means an eerily isolated drive through ghost-town country. But the lake takes weirdness to another level: Rising from the surface are gnarled spires of limestone called tufa towers. Normally an underwater feature, the formations have become visible since water diversions began shrinking the lake in 1951.

If you think the Great Salt Lake is salty, head a little ways west and check out the Bonneville Salt Flats. This 30,000-acre area is encrusted with a layer of salt up to five feet thick, the leftovers from a Pleistocene-era lake that covered parts of three states. It's estimated that the salt flats hold 147 million tons of salt, enough to keep your shaker filled for quite awhile.

Along the coast of the Caspian Sea in Azerbaijan are more than 300 mud volcanoes — which are, yes, basically mini-volcanoes made of mud. The bizarre geological phenomena usually belch mud and gases fairly peaceably, but they can turn violent: In 2001, a mud volcano a few miles from the capital, Baku, spit fire nearly 50 feet in the air.

Shilin translates to “stone forest,” and this set of karst formations in southwestern China’s Yunnan Province really does look like a forest of stone. The stone pinnacles, some of which reach nearly 100 feet toward the sky, are believed to be more than 270 million years old. Visiting after sunset is an especially unearthly experience.

You could be excused for wondering why these trees grow upside down: Madagascar's baobab trees look as if they prefer to sprout their roots out the top, especially during the dry season, when they shed their leaves. The trees put those thick, cylindrical trunks to good use storing precious water.

Koekohe Beach sports some unusual sunbathers: dozens of giant boulders that are almost perfectly round. Called the Moeraki Boulders, the rocks are hollow on the inside, with cracks radiating outward. How did they end up as beach-dwellers? According to Maori legend, the boulders are the remains of baskets, gourds and sweet potatoes that washed up from a wrecked canoe.

Rising from the sea like a giant piece of fan coral is Hvitserkur, a looming, 50-foot-tall piece of former volcano just off Iceland's northern shore. Icelandic legend says it was once a nocturnal troll who got turned to stone by the rising sun, but its name — Hvitserkur means "white shirt" — reflects a more prosaic reality: the droppings of the birds that call Hvitserkur home sweet home