Two large seamounts lie between São Tomé and Príncipe, and between Principe and Bioko. On the mainland, the line starts with Mount Cameroon and extends northeast in a range known as the Western High Plateau, home to the Cameroonian Highlands forests. Volcanic swells further inland are Manengouba, Bamboutu and the Oku Massif.[1] East of Oku there are further volcanic mountains in the Ngaoundere Plateau, some of which appear to have similar origins.[3]