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 rock. The region borders the South Cameroon Plateau to the southeast, the Adamawa Plateau to the northeast, and the Cameroon coastal plain to the south.
The Western High Plateau lies along the Cameroon line, a series of volcanic swells running from the Atlantic Ocean in the southwestern part of the plateau to the Adamawa Plateau in the northeast. The region is characterised by accidented relief of massifs and mountains. The Western High Plateau features several dormant volcanoes, including the Bamboutos Mountains, Mount Oku, and Mount Kupe. The plateau rises in steps from the west. To the east, it terminates in mountains that range from 1,000 meters to 2,500 meters in height, terminating in the South Cameroon Plateau. The plateau gives way to the Adamawa Plateau to the northeast, which is a larger but less accidented region.
The core of the plateau is made up of volcanic rock, which is ringed by plutonic rock. The base is crystalline and metamorphic rock. The base rock is primarily gneiss and granite that dates to the Precambrian period. A layer of basalt covers this. Vulcanism has created fertile black and brown soils. Erosion played a large role.