The length of the Nile between Aswan and the Mediterranean Sea is approximately 1,200 km. Through most of Egypt, the Nile has carved a deep, wide gorge in the desert plateau, often through deposits of sediments it carried for thousands of years before construction of the Aswan High Dam. Immediately north of Aswan, the river valley is narrow with a gentle gradient and is surrounded by sandstone cliffs. These sandstone cliffs give way to limestone cliffs near Esna. Downstream 120 km from Esna, at Qena, the river bends towards the east and the river valley broadens. The Nile valley and floodplain continue to widen northward until the river reaches the delta.
At the south end of the delta, approximately 23 km north of Cairo, the Nile divides into two branches: the Rosetta branch to the west, and the Damietta branch to the east. The delta extends north for another 160 km to the Mediterranean Sea and encompasses about 230 km of Mediterranean coastline. The coastal regions of the delta contain wetlands, lagoons, lakes, and sand dunes. The delta region is densely populated and contains about 22,000 km2 of agricultural land.