Lake Chad At its largest extent the river Mayo Kébbi represented the outlet of the paleolake Mega-Chad, connecting it to the Niger River and the Atlantic. The presence of African manatees in the inflows of Lake Chad is an evidence of that history. Romans reached the lake in the first century of their empire. Indeed, during the time of Augustus lake Chad was still a huge lake and two Roman expeditions were done in order to reach it: Septimius Flaccus and Julius Maternus reached the "lake of hippopotamus" (as the lake was called by Claudius Ptolemaeus). They moved from coastal Tripolitania and
Nigeria (), Niger (), Chad (), Cameroon (), and has a coastline of at least s. Nigeria lies between latitudes 4° and 14°N, and longitudes 2° and 15°E. The highest point in Nigeria is Chappal Waddi at . The main rivers are the Niger and the Benue, which converge and empty into the Niger Delta. This is one of the world's largest river deltas, and the location of a large area of Central African mangroves. Nigeria has a varied landscape. The far south is defined by its tropical rainforest climate, where annual rainfall is a year. In the southeast stands the