city of sharp contrasts, with affluent residential and commercial areas and three universities alongside sprawling slums. It is located along the south bank of the Congo River, downstream on the Pool Malebo and directly opposite the city of Brazzaville, capital of the Republic of the Congo. The Congo River is the second longest river in Africa after the Nile and has the continent's greatest discharge. As a waterway it provides a means of transport for much of the Congo Basin; it is navigable for river barges between Kinshasa and Kisangani; many of its tributaries are also navigable. The river is an important source of hydroelectric power, and downstream from Kinshasa it has the potential to generate power equivalent to the usage of roughly half of Africa's population. The older and wealthier part of the city (ville basse) is located on a flat area of alluvial sand and clay near the river, while many newer areas are found on the eroding red soil of surrounding hills. Older parts of the city were laid out on a geometric pattern, with de facto racial segregation becoming de jure in 1929 as the European and African neighborhoods grew closer together. City plans of the 1920s–1950s featured a cordon sanitaire or buffer between the white and black neighborhoods, which included the central market as well as parks and gardens for Europeans. Urban planning in post-independence Kinshasa has been limited. The Mission Française d'Urbanisme drew up some plans in the 1960s which envisioned a greater role for automobile transportation but did not predict the city's significant population growth. Thus much of the urban structure has developed without guidance from a master plan. According to UN-Habitat, the city is expanding by eight square kilometers per year. It describes many of the new neighborhoods as slums, built in unsafe conditions with inadequate infrastructure. Nevertheless, spontaneously developed areas have in many cases extended the grid street plan of the original city. Administrative divisions Kinshasa is both a city (ville in French) and a province, one of the 26 provinces of the Democratic Republic of the Congo. Nevertheless, it has city subdivisions and is divided into 24 communes (municipalities), which in turn are divided into 369 quarters and 21 embedded groupings. Maluku, the rural commune to the east of the urban area, accounts for 79% of the total land area of the city-province, with a population of 200,000–300,000. The communes