Cameroon line
The Cameroon line (French: Ligne du Cameroun, Portuguese: Linha dos Camarões, Spanish: cordillera de Camerún) is a 1,600 km (1,000 mi) long chain of volcanoes that includes islands in the Gulf of Guinea and mountains on the African mainland, from Mount Cameroon on the coast towards Lake Chad on the northeast. They form a natural border between eastern Nigeria and the West Region of Cameroon.