Lake Oku is a crater lake

Crater lake

A crater lake is a lake that forms in a volcanic crater or caldera, such as a maar; less commonly and with lower association to the term a lake may form in an impact crater caused by a meteorite. Sometimes lakes which form inside calderas are called caldera lakes, but often this distinction is not...

 on the Bamenda Plateau

Western High Plateau

The Western High Plateau, Western Highlands, or Bamenda Grassfields is a region of Cameroon characterised by high relief, cool temperatures, heavy rainfall, and savanna vegetation. The region lies along the Cameroon line and consists of mountain ranges and volcanoes made of crystalline and igneous...

 in the Northwest Region of Cameroon

Cameroon

Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...

. It is located at 2219 metres (7,280.2 ft) on Mount Oku

Mount Oku

Mount Oku, or Kilum Mountain, is the largest volcano in the Oku Massif, in the Cameroon Volcanic Line, located in the Oku region of the Western High Plateau of Cameroon.It is the second highest mountain in mainland West Africa....

, and is completely surrounded by cloud forest

Cloud forest

A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and...

.

The lake lies in an explosion crater formed in the last phase of development of the Oku Massif, a large volcanic field with a diameter of about 100 kilometres (62.1 mi). Mount Oko is a stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 that rises to 3011 metres (9,878.6 ft). The lake is the subject of many myths among the local people.

The lake is the only known habitat of the Lake Oku Clawed Frog

Lake Oku Clawed Frog

The Lake Oku Clawed Frog is a species of frog in the Pipidae family.- Physical description :Lake Oku Clawed Frogs are small, with males growing to an average of 28-31 mm and females 32-36 mm. The name results from the claws at the ends of its four webbed feet. It is grey or brown in colour, with...

. The surrounding Kilum-Ijim Forest

Kilum-Ijim Forest

The Kilum-Ijim Forest is an area of mountain rainforest in Cameroon's North-West Region. It is found on Mount Oku and the nearby Ijim Ridge in the Cameroon mountains, with Lake Oku lying in a crater in its center. It is the largest area of Afromontane forest left in West Africa. The area is an...

 is a nature reserve, set up by BirdLife International

BirdLife International

BirdLife International is a global Partnership of conservation organisations that strives to conserve birds, their habitats and global biodiversity, working with people towards sustainability in the use of natural resources...

, and home to many rare species.