The Delta is a triangular shaped plain, bordering the Mediterranean coastline for approximately 250km (155 miles).Silt has been deposited here by the many tributaries of the River Nile (Rosetta [Rashid], Damietta [Dumyat] and others) and this has made the Delta the most fertile area of Egypt.Its coastline is 2,450 km long which includes the Mediterranean Sea, the Red Sea, the Suez Canal and the Gulf of Aqaba, though any indentations, which are suitable as harbours, are confined to the delta.
From Edfu to Cairo, it is about 23km (14 miles) in width, with most of the arable land lying on the western side.
Just north of Cairo the valley merges with the Delta before the River Nile joins with the Mediterranean Sea.
The River Nile vertically bisects the Sahara Desert and the area to the west is known as the Western Desert, or Libyan Desert, with the area to the East, as far as the Red Sea, being called the Eastern Desert.
The desert itself is very sparsely inhabited with relatively small population centres growing up around oases such as the Fayoum, Siwa, Bahariya, Farafra, Dakhla and Kharga to the west and any areas of habitation being restricted to the many wadis (or valleys) to the east.
Lake Nasser, the world's largest man-made reservoir, was formed by the building of the Aswan High Dam in 1970.