The Nile is the longest river in the world, flowing 6,741km (4,189miles) from its source in the East African highlands to the Delta, a fertile area of about 22,000sq km (8,500sq miles).
The Delta, named by the Greeks because it resembled the share of the fourth letter of their alphabet, lies 17m (57ft) above sea level.
Here the Nile once split into several channels before emerging into the Mediterranean Sea: of these only two now remain.
For most of the length of the Nile Valley, strips of fertile land border either side of the river, and the dividing line between desert and cultivation is clear-cut.
In the temple complex at Kom Ombo, a Nilometer was constructed to gauge the river's rising level during the annual flood.
In 1968 the waters of the River Nile were finally tamed, by the construction of the Aswan Dam.
The Nile Valley is no longer flooded every year, and this has made a huge difference to Egypt's natural environment and way of life.
