Forest Guinea possesses unique wildlife and geological diversity. It is characterized by undulating lowlands, which are frequently disrupted by suddenly rising high mountain ranges and eroded plateaux of the Guinea Highlands. In general, the lowland areas are covered by forest-savanna mosaics and lowland forests; but all ridges and plateaux are covered by montane forests above 600 meters. Remarkable sky islands are the Mount Nimba (1720 meters), Simandou Massif (1658 meters), Ziama Massif (1387 meters), Mount Tétini (1257 meters), Kourandou Massif (1236 meters), and Mount Béro (1210 meters). All of them belong to the south-eastern part of the Guinea Highlands, and remained poorly discovered by science. The most prominent protected areas in Forest Guinea are the Mount Nimba Strict Nature Reserve, the Ziama Massif, and the Diécké Classified Forest.