Majestic mountains and sparkling seas always attract travellers – but sometimes nature has a bigger trick up her sleeve. To track down some of the world’s strangest sights, we turned to question-and-answer site Quora, asking: What are some of the best rare natural phenomena that occur on Earth?

From Australia’s bubblegum-pink lake and a blood-red waterfall in Antarctica to a secret beach-in-a-hole in Mexico and a US valley where stones eerily move, these seven spots are Mother Nature’s eyeball-popping sideshow.

Frozen methane bubbles, Canada

They look otherworldly, like flying saucers that dropped into the water and froze, or ancient, ice-encapsulated jellyfish. In fact, these icy circles are frozen methane bubbles – pockets of gas that, when trapped underwater and frozen, form a spectacular landscape.

Found in winter in high northern latitude lakes like Lake Abraham in Alberta, Canada, these gas bubbles are created when dead leaves, grass and animals fall into the water, sink and are eaten by bacteria that excrete methane. The gas is released as bubbles that transform into tens of thousands of icy white disks when they come into contact with frozen water, Quora user Mayur Kanaiya explains.

It’s a stunning, but potentially dangerous sight. This potent greenhouse gas not only warms the planet, but also is highly flammable. Come spring, when the ice melts, the methane bubbles pop and fizz in a spectacular release – but if anyone happens to light a match nearby, the masses of methane will ignite into a giant explosion.

Curious travellers can see these gassy hiccups in lakes across Canada’s Banff National Park, or in the Arctic Ocean off Siberia, where researchers have found gargantuan gas bubbles as large as 900m across.

Blood Falls, Antarctica

The name says it all. Blood Falls, in East Antarctica’s McMurdo Dry Valleys, looks like slowly pouring scarlet-red blood, staining snowy white Taylor Glacier and Lake Bonney below. It’s a surprising – and creepy – sight to behold.

The trickling crimson liquid isn’t blood, however. Nor is it water dyed by red algae, as early Antarctica pioneers first speculated. In fact, the brilliant ochre tint comes from an extremely salty sub-glacial lake, explains Quora user Aditya Bhardwaj.

About two million years ago, a hyper-saline body of water became trapped beneath Taylor Glacier, isolated from light, oxygen and heat. As the saltwater trickles through a fissure in the glacier, it reacts with the oxygen in the air to create this spectacular, rust-hued cascade.

It’s a visual and scientific wonder, and Taylor Glacier – accessible only by helicopter from McMurdo Station or Scott Base, or cruise ship in the Ross Sea – is the only spot on Earth to see it.

Sailing Stones, US

When visitors stumbled upon scores of heavy stones that appeared to have moved across the dried lake bed of Racetrack Playa in California’s Death Valley National Park, leaving a tell-tale trail in their wake, scientists were baffled. How had so many boulders, some weighing 300kg, moved as much as 250m across this remote part of the valley, asks Quora user Farhana Khanum?

Adding to the mystery, some trails were gracefully curved, while others were straight with sudden shifts to the left or right. Who, or what, had moved the stones? A slew of theories emerged, from magnetic fields to alien intervention to dust devils to pranksters.

It took a NASA scientist to crack the case. In 2006, Ralph Lorenz developed a kitchen table model using a small rock frozen in an inch of water in a Tupperware container to demonstrate ice shove, the phenomenon behind the mysterious sailing stones.

In winter, Racetrack Playa fills with water and the lakebed’s stones become encased in ice. Thanks to ice’s buoyancy, even a light breeze can send those frozen boulders sailing across the muddy bottom of the lakebed. Stones with rough bottoms leave straight tracks, while those with smooth bottoms drift and digress. Warmer months melt the ice and evaporate the water, leaving only the stones and their mysterious trails. 

Visitors can see these sailing stones in a few locations, including Little Bonne Claire Playa in Nevada and most famously, Death Valley’s Racetrack Playa.

Kawah Ijen Lake, Indonesia

Travellers flock to the Indonesian island of Java to see the magnificent Kawah Ijen volcano – but what they don’t expect to find is the stunning turquoise-hued caldera lake at the volcano’s summit. To add to the drama, bright, citrine-coloured stones and billows of white gasses surround the 1km-wide aquamarine lake in a spectacular show.

One element is responsible for the entire, striking scene: sulphur. The magma chamber below the volcano pours sulphuric gases into the lake. Combined with a high concentration of dissolved metals, the gases turn the water a brilliant shade of blue. They also render the Ijen crater-lake the world’s largest highly acidic lake with a pH of 0.5.

That same chamber blasts a continuous stream of sulphuric gas from lakeside fumaroles that swirl around the lake. When the gas condenses and falls to the ground, it dyes the lake’s surrounding stones a shocking shade of electric yellow.

“Hydrogen chloride released from Ijen volcano mixed with the lake and turned it into an acidic monstrosity that it is today,” writes Quora user Vinay Sisodia. “What makes this place even more stunning, especially at night, is shots of sulphuric gases that combust into glints of bright blue upon contact with air.”

Intrepid travellers can join three-hour hikes to the bank of the crater to experience the lake in person.

Hidden Beach, Mexico

It’s a vacationer’s dream: a secret beach tucked away from the masses, with shade, sun and pristine water. And this dream comes true at Playa Del Amor, more commonly known as Hidden Beach, on one of the Marieta Islands off the coast of Mexico.

The unlikely source of this magical little secret: a bomb blast, according to Quora user Siddhartha Das. Mexico began testing bombs in the uninhabited Marieta Islands in the early 1900s, resulting in a gaping hole in the surface of one of the islands. Over time, tides filled the hole with sand and water, creating a secluded watery Eden where determined beach bums can swim, sunbathe and kayak largely out of sight.

Playa Del Amor, literally Lover’s Beach, is invisible from the outside, but visitors can access it through a 24m-long tunnel that links the secluded beach to the ocean.

Pink Lake Hillier, Australia

Fly over Western Australia for a rare visual treat: nestled among dense emerald-green woodlands surrounded by the deep blue of the Southern Ocean are a series of lakes in a shocking shade of bubblegum pink.

One of the most well known is Lake Hillier, a 600m-long lake on the edge of Middle Island in the Recherche Archipelago off Western Australia’s south coast. Surrounded by a thin ring of sand and an expansive forest of paperbark and eucalyptus trees, the rosy pink lake punctuates a stunning landscape.

But even more surprising than its Pepto-Bismol shade is that “nobody seems to be able to definitively explain its distinctive colour,” according to Quora user Garrick Saito. Possible causes include the presence of green algae that can accumulate high levels of beta-carotene, a red-orange pigment; haloarchaea, a type of microorganism that appears reddish in large blooms; or a high concentration of pink brine prawn.

Most tourists admire the chromatic splendour of Lake Hillier from a helicopter or plane ride. For on-the-ground visitors, there’s an added treat: Lake Hillier is highly saline but the water isn't toxic, so pack your swimsuit and go for a swim. Thanks to its high salinity, you’ll bob like a cork.

Fairy Circles, Namibia

Across the arid grasslands of the Namib Desert lies an eerie sight: millions of circular patches of land void of plants, each between 2m and 15m in diameter, arranged in a honeycomb-like pattern across 2,500km of land. These disks of bare soil, known as fairy circles, pockmark the landscape in Namibia, as if giant moths ate through the vast carpets of grassland.

Adding to the mystery, no one knows for certain what causes these otherworldly formations, writes Quora user Prem Rathaur. But there’s no shortage of theories.

Scientists have suggested radioactive soil, or that toxins released from plants kills the vegetation in circular patterns. Others believe the circles are the work of sand termites. To store water, they burrow in the soil in ring-like patterns and consume the roots of vegetation to allow underlying grains of sand to absorb falling rain.

Another hypothesis ascribes the circles to competition for resources. In harsh landscapes, plants compete for water and nutrients. As weaker plants die and stronger ones grow, vegetation “self-organizes” into unusual patterns. 

Considering the eerie beauty of these phenomena, perhaps the most fitting theory is that of local bushmen, who say fairy circles are nothing less than the footprints of gods.

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