The Caucasus, a large, culturally diverse region traversed by its eponymous mountains, is bounded by the Black Sea to the west and the Caspian Sea to the east. The region north of the mountains was a production center for grain, cotton and heavy farm machinery, while its two main oilfields, at Maykop, near the Black Sea, and Grozny, about halfway between the Black and the Caspian Seas, produced about 10 percent of all Soviet oil. South of the mountains lay Transcaucasia, comprising Georgia, Azerbaijan and Armenia. This heavily industrialized and densely populated area contained some of the largest oilfields in the world. Baku, the capital of Azerbaijan, was one of the richest, producing 80 percent of the Soviet Union's oil—about 24 million tons in 1942 alone.