The World’s Strangest Natural Wonders
It’s a far cry from the stereotypical landscapes of clear blue lakes, rolling green hills, and white-sand beaches that inspire most travelers—and that’s part of what makes strange natural wonders like Spotted Lake so thrilling. A recently discovered cave that grows crystals the size of four-story buildings, a lake the color of a strawberry milkshake, and a glacier that seems to bleed sound like they’re from another planet, but can be seen right here on earth, and they remind us that there’s plenty of mystery left to explore.
For billions of years, our planet has been a work in progress. Wind, water, pressure, minerals, heat, and lesser-understood forces mold and shape our environment, carving out caves and canyons, flooding and drying lakes, shaping mountains, shifting shorelines, moving the ground beneath our feet, and creating all manner of strange formations.
Related: America's Most Beautiful Lakes
Long before scientists were able to offer explanations for the world’s more curious natural achievements, locals have been coming up with their own ideas. Māori legend says the enormous boulders found on New Zealand’s Moeraki Beach are the washed-ashore gourds and sweet potatoes from the wreck of a mythological canoe, while Irish folklore attributes the creation of the Giant’s Causeway to a quarrel that spanned across the sea to Scotland.
Such bizarre formations are, in fact, the result of time and pressure working against soil and rock, an often slow and methodical process that yields showstopping results. Others are the result of a sudden dramatic shift in conditions. Together, they caution us, as author Will Durant wrote in the January 1946 edition of Ladies Home Journal, that “civilization exists by geological consent, subject to change without notice.”
Seeing is believing, so take our tour of the strangest natural wonders—and keep an eye out for what the powerful planetary forces may do next.
Salar de Uyuni, Bolivia
When a prehistoric lake dried up about 30,000 years ago, it left an endless expanse of white hexagonal tiles that stretch to the horizon. Welcome to the world’s largest salt flat, stretching for 4,000 square miles—25 times the size of Utah’s Bonneville Salt Flats. The site provides more than 25,000 tons of salt per year to local miners, supports a thriving community of thousands of flamingos, and attracts tourists who can check into the Palacio de Sal, a 16-room hotel made entirely from salt blocks.
Asbyrgi Canyon, Iceland
Legend has it that the Asbyrgi Canyon in northern Iceland was created when the hoof of a Norse god’s horse touched the earth, slicing through 300-foot-tall cliffs and flattening an area just over two miles long and more than a half mile wide. The likelier scientific explanation is that two periods of glacial flooding carved the canyon between 3,000 and 10,000 years ago. But standing atop the cliffs, with the green carpet of the horseshoe-shaped canyon spread before you, it’s fun to imagine otherwise.
Lake Retba, Senegal
It looks as if someone poured a giant bottle of Pepto-Bismol into Lake Retba—that’s how deeply pink these waters are. The color is actually caused by a particular kind of algae called Dunaliella salina that produces a pigment. The salt content is extremely high, reaching 40 percent in some spots and allowing the algae to thrive (and swimmers to float effortlessly on the surface of the 10-foot-deep lake). Blinding white piles of salt line the shores, and locals work several hours a day harvesting salt from the bright pink water.
Marble Caves, Chile
Six thousand years of wave erosion created the undulating patterns that give these caves their marbleized effect, enhanced by the reflection of the blue and green water of Carrera Lake, near Chile’s border with Argentina. Although the area is threatened by a plan to build a dam nearby, for now, visitors can kayak throughout the caves on days when the waters are calm.
Travertine Pools at Pamukkale, Turkey
People have sought the reputed healing effects of bathing here for thousands of years. The water that flows from 17 subterranean hot springs into the pools has an extremely high concentration of calcium carbonate, which forms soft deposits when it hits the surface. Those viscous white deposits harden over time until the springs resemble a fountain made of chalk or, as indicated by the poetic translation of Pamukkale, a “cotton castle” visible from more than 10 miles away.
Sailing Stones, Racetrack Playa, Death Valley, CA
No one has ever seen one of the “sailing stones” on Death Valley’s Racetrack Playa move, but evidence of their travels is visible in the long track marks that trail behind them in the dusty ground. Scientists aren’t sure exactly how the rocks—which can weigh hundreds of pounds—make their way across the dry lake bed. The prevailing theory is that when the rocks are wet or icy, they’re pushed along the flat playa by strong winds. The deep groove marks they leave behind indicate they may travel up to 700 feet from their point of origin.
White Desert (Sahara el Beyda; Egypt
Bulbous white rocks in strange shapes and sizes rise from the desert about 28 miles north of the town of Farafra in western Egypt—a cluster of mushrooms here, a herd of half-melted snowmen over there. Their appearance isn’t due to some avant-garde stone sculptor, but rather thanks to the wind. When the ancient sea that once covered the land dried up, the remaining sediment layer began to break down. The softer spots crumbled away, and over time, powerful sandstorms shaped the harder rocks into their current forms.
Moeraki Boulders, New Zealand
The spherical stones that line New Zealand’s Moeraki Beach reach up to seven feet in diameter and have been compared to everything from the marbles of giants to colossal dinosaur eggs to half-submerged prehistoric turtles, ready to stand up and shake off the sand at any moment. They’re actually concretions, masses of compacted sediment formed below ground more than 50 million years ago. As the sand that surrounds them erodes, they seem to rise to the surface as if pushed up from the center of the earth. The stones are also found on Bowling Ball Beach in Mendocino, CA, as well as elsewhere in the U.S. and Canada and Russia.
Caño Cristales River, Colombia
Folks make the journey into central Colombia’s Serranéa de la Macarena national park to see why Caño Cristales has inspired nicknames like the River of Five Colors, the Liquid Rainbow, and even the Most Beautiful River in the World. It’s important to get the timing right: when the water reaches the perfect levels (usually between July and December), it becomes a kaleidoscope of pink, green, blue, and yellow as a plant called the Macarenia clavigera, which lives on the river floor, gets the sun it needs to bloom into an explosion of colors.
The Eye of the Sahara (Richat Structure; Mauritania
This enormous depression, circular in shape and stretching 25 miles wide, is like a bull’s-eye mark in the middle of an otherwise flat and featureless area of Mauritania desert. Visible from space, it has been a landmark for astronauts since the earliest missions. The Eye isn’t the result of any target practice by aliens; rather, it formed as winds eroded the different layers of sediment, quartzite, and other rocks at varying depths.
Spotted Lake, British Columbia
It looks almost as if you could play Twister on Spotted Lake near Osoyoos, less than a mile from the Washington State border. Each summer, most of the water in this mineral-rich lake evaporates, leaving behind large concentrations of salt, titanium, calcium, sulfates, and other minerals that form a polka-dot pattern in shades of green, yellow, and brown circles of varying size. The lake is a sacred site to the First Nations of the Okanagan Valley, and the land on which it sits is private property owned by the Indian Affairs Department. You won’t actually be able to get up close to the lake, but you can get a good look from the nearby road.
The Stone Forest (Shilin; China
Many of the trees within the forest in China’s remote Yunnan Province are rock hard, literally. The area, which spans nearly 200 square miles, was underwater 270 million years ago, and the sea floor was covered with limestone sediment. Gradually, the seabed rose and the water dried up. As rain and wind eroded the weaker rock, the stronger limestone spires began to take shape. Now they rise skyward, surrounded by leafy trees.
Blood Falls, Antarctica
A shockingly macabre shade of what looks like blood cascades down the pale face of Taylor Glacier. When scientists first discovered these falls in the McMurdo Dry Valleys in 1911, they thought algae colored the dark red water that spewed from a crack in the glacier. It turns out the hue comes from high iron levels in the falls’ source, a pool buried 1,300 feet below the ice. In a sinister twist, the landscape is so arid that when seals and penguins wander inland and get lost, they never decompose; their remains are left strewn about.
The Cave of the Crystals, Naica, Mexico
It looks like Superman’s Fortress of Solitude come to life. A thousand feet underground in a working lead and silver mine in Chihuahua, Mexico, opaque crystals of gypsum—some as large as four feet wide and 50 feet long—sprout at all angles from the volcanically heated water below. Temperatures in the cave, which was discovered only in 2000, can reach 150 degrees with nearly 100 percent humidity, conditions that only a superhuman could survive in for long. Any more than 10 minutes in a cave without proper gear can lead to heatstroke.
Giant’s Causeway, United Kingdom
One of Northern Ireland’s most popular tourist attractions, Giant’s Causeway earned its name from the 40,000 basalt columns that interlock to form what looks like a walkway fit for a colossus. The stones, mostly hexagonal in shape, formed 60 million years ago when underground lava flows cooled into formations as tall as 39 feet high and 18 inches in diameter. It was comparatively recently—about 15,000 years ago—that the soil around the seaside stones eroded and they became visible above ground.
The Wave, Coyote Buttes, AZ and UT
Wind and rain have worked their magic, eroding lines that swoop and swirl across the sandstone formation. The result, which resembles a cresting wave, is one of the most photographed—if not easy to reach—spots in the American West. A permit is required to make the unmarked hike to the Wave, and only 20 are given out daily. It’s almost easier to make the journey to southwest Australia to see the Wave’s down under counterpart, Wave Rock.
White Sands National Monument, New Mexico
There are sugar-white dunes moving through the Chihuahuan Desert of New Mexico at a rate of nearly 30 feet per year. As the mineral-rich water of nearby Lake Lucero evaporates, it forms gypsum deposits that are then shaped by the wind into these dunes. Since the early 1900s, visitors have been here to hike; ranger tours and bus tours along the 16-mile Dunes Drive are also offered through the National Parks Service.
Silfra Rift, Þingvellir National Park, Iceland
The shifting of the tectonic plates that fit together like puzzle pieces on the earth’s crust (a.k.a. continental drift) is more visible in southwest Iceland’s Þingvellir National Park than anywhere else. In the park’s ever-widening Almannagjá canyon, you can walk in the seam of the Eurasian and North American plates as they slowly move apart—or you can dive into the crack between continents in the Silfra Rift in Lake Þingvellir. It takes nearly a century for glacier ice to melt and filter through lava into the lake, but once the water gets there, it’s so clear that visibility underwater is nearly 1,000 feet.
Ice Towers of Mount Erebus, Antarctica
On the frozen slopes of Mount Erebus, above the world’s most southerly active volcano, superheated gas rises through steam vents to form caverns in the ice. When the volcanic gas passes through the caves, some of it freezes inside, forming gnarled chimney towers that can reach heights of more than 60 feet. The result is a landscape of icy smokestacks belching steam into the freezing Antarctic air like a cluster of magical factories.
Devils Marbles, Australia
Known to the Aborigines as a sacred place called Karlu Karlu, the Devils Marbles Conservation Reserve gives Ayers Rock some serious competition as the Northern Territory’s most iconic site. Most photos focus on just two of the rocks, but there are actually many more of these prehistoric rust-colored granite boulders—some of which can be as large as 20 feet in diameter—strewn over an area of 4,400 acres.
Tessellated Pavement at Eaglehawk Neck, Tasmania
The coastline of the Tasman Peninsula is unlike any other in the world thanks to a rare erosion effect named after a Roman mosaic technique called tessellated pavement. There are two different patterns produced by the erosion: some of the rock pieces are formed into rounded bricks that resemble loaves of bread, while others develop depressions that collect saltwater between their raised borders, reflecting the sky like a window frame that stretches to the sea.
Sarisariñama Sinkholes, Venezuela
On the flat-topped mountain of Cerro Sarisariñama in southwest Venezuela, gravity has punched four perfectly circular holes nearly 1,000 feet deep into a landscape of remote rainforest. Hundreds of miles from the nearest road, the area is so far removed from civilization that the sinkholes weren’t discovered until 1961, when they were spotted by a pilot flying over the mountain.
Puerto Princesa Subterranean River, Philippines
The five-mile-long Puerto Princesa Subterranean River on the island of Palawan is the world’s longest navigable underground river. It flows to the South China Sea through a nearly 15-mile-long cave that’s lined with stalactites and stalagmites and contains the largest cave chamber in the world. The surrounding park is a UNESCO World Heritage Site that’s equally impressive and is home to more than 800 plant species, 165 kinds of birds, 30 mammal species, 19 varieties of reptiles, and nine different species of bats.
Chocolate Hills, Philippines
There are two popular legends that explain the formation of the Chocolate Hills, the nearly 2,000 symmetrical mounds that rise as tall as 400 feet above the surrounding farmland of Bohol Island. One claims that they’re the mess left behind by two giants who had a boulder fight. The other says that the hills are the tears of a giant mourning the death of his lover. But many visitors may prefer the sweeter image of the grass-covered limestone hills, which turn a rich shade of brown in dry season, as resembling the massive Hershey’s Kisses that inspired the landscape’s name.
Luray Caverns, Virginia
In a 400-million-year-old cave system in rural Virginia you’ll find the world’s largest musical instrument. Visitors have been coming to the Luray Caverns to see limestone columns, stalactites, and stalagmites since the site’s discovery in 1878, and while the natural beauty of the underground world is its own draw, the main attraction is the Great Stalacpipe Organ, built in 1954. When the keys of the organ are pressed, a rubber mallet taps the cluster of nearby stalactites, producing varying tones that echo throughout the site’s sprawling network of caves.
Waitomo Glowworm Caves, New Zealand
Quarter-inch-long bioluminescent glowworms that radiate a tiny blue light dangle from the ceiling of these caves deep in the lush, subtropical hills of New Zealand’s North Island. Visitors ride in an inflatable raft along the underground Waitomo River with Spellbound Glowworm & Cave Tours. Slowly adjusting to the darkness, they admire what looks like a turquoise starscape.
Why It’s Cool: Glowworms, which dangle sticky, filamentous “fishing lines” to catch insects, are scattered throughout many other caves, but their densely concentrated numbers here make this grotto unique in the world.
Socotra Archipelago, Yemen
Sitting alone at the junction of the Red Sea and the Indian Ocean, the Socotra Archipelago has enjoyed almost uninterrupted isolation since it broke off from the super-continent of Gondwana (the land mass from which the Americas, Africa, Australia, Arabia, and India emerged) 100 million years ago. Since then, Mother Nature has evolved in many weird and wonderful ways. This Unesco World Heritage Site is home to exotic flora (trees that ooze bloodred sap; some that bear foul-smelling, poisonous cucumbers; and others shaped like bottles), 180 exotic birds, and 700 plant and animal species found nowhere else on earth.
Traveler’s Tip: Don’t bother brushing up on your Arabic. The local Socotri language, spoken by the 40,000 inhabitants, is unique in this world—just like the environment.