Encyclopedia Congo Pronunciation Key Congo or Zare , great river of equatorial Africa, c.2, 720 mi (4, 380 km) long, formed by the waters of the Lualaba River and its tributary, the Luvua River, and flowing generally N and W through Congo (Kinshasa) to the Atlantic Ocean. Sections in this article: Introduction Course Economic Importance European Exploration Bibliography conglomerate, in geology ...