The Biu Plateau is a highland area in Southeastern Nigeria containing many recently extinct volcanoes. It covers about 5,200 km² (2,000 sq mi) and has an average elevation of 700 m (2,300 ft). The plateau lies between the Upper Benue Basin to the south and the Chad Basin to the north. High points are Wade Hill at 775 m (2,543 ft) above sea level and Wiga Hill, at well over 800 m (2,600 ft). The plateau is the source of many tributaries of the Gongola River, which have cut deep gorges.