The spread of Congo's irregular 300,000 plus square kilometers runs north to southwest. There are three geophysical zones, one of them discontinuous. Near the Atlantic coast is a plain with mangroves and small lakes. Beyond the plain, hills rise to the central African plateau, locally called Plateaux Batéké. These highlands end as one goes north, tilting down into the Congo Basin. But they continue along the western and northwestern borders, and in a small protrusion of the nation in the northwest. Heights reach nearly 1,000 meters(1). Both the highlands and the basin are covered with forest and grassland.
Only one river cuts through the highlands to let water out of the basin: the Congo(2). This river forms the nation's southeast boundary. Its principal right bank tributary, the Oubangui(3), forms the remainder of the eastern boundary. The basin's rivers flow south, like the Sangha, or east, lke the Alima, to join the Oubangui or Congo.
West of the plateau the chief rivers are the Kouilou, and its main feeder, the Niari.
There is no majority for any single language. French is the official administrative language but it is almost purely a second language. The single most important mother tongue is a Kongo(4)-based creole, Kituba(5), spoken by about one in three, mostly from the capital westward to the coast. Only two other languages are native to more than one in 20: Teke-Nizikou, in Plateaux Province, by about three in 20, and Yombe, in Kouilou Province, by about one in ten. All three, along with many other local ones, are Narrow Bantu(6) languages, and this group accounts for the majority
It isn't clear what the religious breakout is. Christians are probably the plurality, if not a majority. Of them, Roman Catholics outnumber Protestants. Estimates of indigious religions's adherants vary from around one in twenty(7) to nearly one in two. Estimates of Moslems vary from less than one in a hundred to three in twenty(8).
Of the Christians, syncretism is common. Thus crucifixes perform many functions that were once done by fetishes of local origin. Clay-covered magic dolls are still in wide circulation, both Bakongo (nkisi) and Teke versions, and are said to be possessed by good or usefully malevolent spirits. Which kind of spirit is embedded depends on the mode of manufacture.
There is only one city with a million residents: Brazzaville, the capital, part of the Kinshasa-Brazzaville metropolitan area.
Bantu speakers moved into the area from the north starting almost 4,000 years ago, and completed their migration by no later than 300 C.E. Pygmies(9) were there before them.
Speakers of Ngbandi languages moved into the lower Oubangi valley in the last millenium.
Three kingdoms helped promote individual local languages. South of this area was Kongo; its trade influence led to the development of the creole, Kituba. The kingdom of Tio left behind a set of Teke languages on the plateau. And the coastal Kingdom of Loango advanced Vili, though few speak it any more.
Europeans introduced Christianity but its influence was minimal until the 20th century.
north, from the northeast
east, from the northeast
east, from the southeast, and south
southwest
north, from the southwest, and west
north, from the northwest
(1) The plateau's edge is sometimes called the Crystal (Cristal) Mountains.
(2) Africa's second longest, the world's eighth.
(3) Or Ubangi.
(4) Or Congo.
(5) Called Munukutuba in Brazzaville.
(6) Subdivisions of Bantu are controversial. I used ethnologue.com (viewed 2/2006).
(7) Generally, Christian sources.
(8) Only one source for the large figure, a world survey of Islam.
(9) Pygmies now speak Bantu languages too.