The Nile Delta marks the location in northern Egypt where the Nile River empties into the Mediterranean Sea. Because most rivers deposit silt in the shape of a triangle, resembling the Greek letter delta, the mouth of a river is called a delta.
Prior to Egypt's construction of the Aswan High Dam in 1971, the Nile would flood annually, leaving a layer of rich alluvial soil in its wake. In ancient times, the Nile split into seven branches at the delta; however, there are fewer branches today due to centuries of human construction projects. Cairo, the largest city in Africa and capital of Egypt, is located in this area.