Lake Nyos was formed thousands of years ago when a volcano erupted and left behind a deep bowl-shaped crater. Over time, rainwater filled the crater and created the lake. Today it sits about 1,800 metres above sea level, surrounded by steep green hills. The water is famously vivid blue-green, caused by minerals dissolved in it from the volcanic rocks below.
Beneath the surface of Lake Nyos, carbon dioxide gas seeps up slowly from underground volcanic activity. This makes the lake scientifically unique and fascinating to study. Scientists have installed pipes in the lake to let the gas escape safely and have been monitoring it closely since the 1980s. The lake has become an outdoor laboratory for researchers from around the world.
The area around Lake Nyos is quiet and very beautiful. The narrow roads through the highlands leading to the lake pass through lush farmland and small villages where local people keep cattle and grow crops. The lake itself reflects the sky and surrounding hills so perfectly that on calm days it is hard to tell where the water ends and the sky begins.
Researchers studying Lake Nyos have made important discoveries about how volcanic gas behaves in deep water. The knowledge gained here is now used around the world to make other crater lakes safer. In this way, a small, remote lake in Cameroon has contributed to science used globally.