This lake in Cameroon is one of the world's only known exploding lakes. Just underneath it, a pocket of magma fills Nyos with carbon dioxide and transforms its water into carbonic acid.
As recently as 1986, the lake burped a massive plume of carbon dioxide, suffocating as many as 1,700 people and 3,500 livestock from nearby villages. It was the first known large-scale asphyxiation ever recorded from a natural event.
There is still concern that this event could repeat itself in one of the world's three exploding lakes. In fact, Nyos may be the most susceptible of the three to cause another disaster because the natural dike that contains the lake is weak and vulnerable to cracking.