Where is Lake Nyos? Lake Nyos is a crater lake in the Northwest Region of Cameroon in Africa, located about 315 km (196mi) northwest of Yaoundé, the capital.  Lake Nyos Eruption  A limnic eruption at Lake Nyos erupted on August 21, 1986  which killed 1,746 people and 3,500 livestock. The Lake was located in northwestern Cameroon. Lake Nyos sits high in a volcanic plain bounded by the Cameroon line of volcanoes, which stretches into the Gulf of Guinea. The lake itself fills a circular maar, formed when groundwater meets hot lava or magma and explodes. The hole from the eruption eventually fills the water, forming a crater lake. In August…