A cloud of deadly gas settled over the region, suffocating anyone in its path. As locals lay in bed, Lake Nyos quietly released a gigantic bubble of CO2, like the Earth was exhaling. In 1986, this is exactly what happened in Cameroon. They could’ve been killed by a nearby lake. Was it a terrorist attack? A virus? The answer could be even weirder.

You wonder what could have killed all these people. Bodies lie in the streets, an expression of fright etched on their dead faces. You arrive home from a weekend away, to find your neighborhood full of corpses. Over time, the valley filled with water, eventually becoming the skeleton-haunted Roopkund Lake. It’s now thought this is a folk memory of a real event, and a freak hailstorm that dropped baseball-sized chunks of solid ice killed all 200 pilgrims in the valley when they couldn’t reach shelter. There’s an old song from the region around Roopkund, about a mountain goddess who smote a bunch of travelers with a titanic hailstorm. So what could have caused 200 people to die in this way? The eventual answer scientists came up with was hailstones.

On top of that, they’d all been killed in a similar way: with a blow to the head that cracked their skulls. When the bones were examined, it turned out that they all dated to around 850 AD. It being wartime and all, the Brits naturally assumed that they were at the scene of a Japanese massacre. Yet that’s exactly what British troops found in Roopkund Lake in the winter of 1942. The decaying remains of hundreds of humans who’ve died a terrifying death is another. There are certain things you never want to find in any body of water. In the heat of Tunisia, even a lake full of green sludge is better than no lake at all. Not that that stopped locals from bathing in it. One local resident said he’d passed the remote area only three weeks beforehand and it had been dry as a bone.Īlthough Gafsa Lake started out a cool, inviting blue, it quickly became full of algae, and possibly toxic to humans.

Scientists think that some rupture in the rock above the water table resulted in the sudden appearance of Lake Gafsa, as below-ground water was sucked up onto the surface. Gafsa is an area that has seen lots of mining in its past, much of it unregulated. A lake that just happened to be the most-inviting shade of azure. Imagine their surprise when they got there and found a giant freakin’ lake where their meadow used to be. One day in 2014, a group of Tunisian shepherds were making their way to a familiar patch of land. Apparently, Gafsa Lake in Tunisia never got the memo. Pretty early on in life, most of us learn that things don’t just appear from nowhere.

Lake natron animals statues