The Biu Plateau is a highland area in Northeastern 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. To the north the plateau slopes gently to the Bauchi plains and the Chad Basin.