Lake Nyos

Lake Nyos closes the list of most beautiful lakes in Cameroon. Located around 315 kilometers (196 miles) northwest of Yaoundé, the country's capital, Lake Nyos is a crater lake in the Region of Cameroon. In the Oku volcanic plain near the Cameroon line of volcanic activity, Nyos is a deep lake perched high on the face of a dormant volcano. The lake's water is held back by a volcanic dam.

Under the lake, there is a pocket of magma that seeps carbon dioxide (CO2) into the water, turning it into carbonic acid. Only three lakes are known to be as saturated with carbon dioxide, and Nyos is one of them. As a result, it is vulnerable to limnic eruptions (the others being Lake Monoun, also in Cameroon, and Lake Kivu in the Democratic Republic of Congo and Rwanda).

In 1986, Lake Nyos abruptly released a significant cloud of CO2, presumably as a result of a landslide, which suffocated 1,746 people and 3,500 cattle in adjacent towns and villages, the most noteworthy of which was Chah, which was abandoned as a result of the catastrophe. It wasn't entirely unusual, but it was the first instance of a significant asphyxiation brought on by a natural occurrence. A degassing tube that siphons water from the bottom layers to the top, enabling the carbon dioxide to leak in safe amounts, was built in 2001 to stop a repeat of the incident. In 2011, there were added two tubes.

The lake is currently dangerous since its natural wall is eroding. This natural levee might give way as a result of a geological tremor, causing water to flood into settlements downstream all the way into Nigeria and allowing significant volumes of carbon dioxide to escape.

Location: northwestern Cameroon