and granite created by the flow of the river over many centuries.

Below Aswan, the cultivated floodplain strip widens to as much as twenty km. North of Isna (160 km north of Aswan), the plateau on both sides of the valley rises to as much as 550 m above sea level; at Qina (some 90 km north of Isna) the 300-m limestone cliffs force the Nile to change course towards the southwest for about 60 km before it turns northwest for about 160 km to Asyut.