Geographers refer to northern Nubia as "Lower Nubia" and to southern Nubia as "Upper Nubia." The reason for this is because the Nile River in Nubia, unlike other rivers of the world, flows from the south to the north. So up the Nile is actually going south.
The Nubian section of the Nile contains six rock filled rapids called cataracts.
It was from the south that the original ancestors of the Egyptians, following the direction of the Nile River north, settled the land of Egypt. The Egyptians themselves recorded in their writings that their ancestors came from the south. The Edfutext is an inscription still found in the Temple of Horus at Edfu. It tells us that the origin of Egyptian civilization was taken from the south by a band of invaders led by King Horus.
The Nile River flows from Central Africa to the Mediterranean Sea some 4,000 miles.
The Nile (and its tributary rivers) is the single most dominant feature of the physical landscape. The river system cuts across the climatic and vegetation belts, providing water for irrigation, a major means of transportation, and the locus for most of the settled agricultural life and economy of the country. The Nile is formed by the confluence of two great rivers, the Blue and White Niles, at the Mogren in Khartoum. The Blue Nile rises from Lake Tana (Dambea) in the Ethiopian highlands and contributes most of the floodwaters since the White Nile loses a great percentage of its water by evaporation in the Sudd swamps. The only major tributary north of Khartoum is the seasonal Atbara River.
Different regions of ancient Nubia and its hinterland can be identified. Once can see the dominant topological features as follows: 1) the Upper Nile drainage system, 2) the great eroded region of the Red Sea mountains, 3) the vast central plains with occasional sharp hills, 4) the volcanic uplands in Darfur, and 5) the southern and southeastern highlands of the Nuba Hills. Generally, Nubia is built on a sandstone fountain with areas of volcanic and granite infusion along with other hard stones with important human use in construction and sculpture. Emeralds and gold are also found in the deserts of Nubia.
Economic classification can be refined within four subregions: 1) the Nile valley in the north and central parts, where most people farm with the aid of irrigation; 2) the western Sudan, an area of mixed nomadism and peasant agriculture; 3) the eastern Sudan, primarily an area of nomadism but with some irrigated agricultural areas; and 4) the southern region, with a wide variety of pastoral and complex agricultural societies.
The history of agriculture in Nubia and along the Nile is a vast topic. Agriculture involved the imported grains that included emmer wheat for making beer and barley for making bread. In Nubia, millet was especially important and may have had local domestication. Root crops were not as important in the Nile valley as they were in sub-Saharan Africa, and bananas did not enter until far later. Animal husbandry included the earliest domestication of sheep, goats, pigs, and cattle. They arrived within the Neolithic horizons of the Nubia A-Group (3800-3100 B.C.), and its Predynastic Egyptian counter-parts. Horses probably did not arrive in numbers until the time of the Hyksos, and camels likely entered the region in Assyrian times or before.