West Sumatra (Sumatra Barat) is in Sumatra, Indonesia.
West Sumatra bounded in the north by the province of North Sumatra, in the west by the Indian ocean, in the south by the provinces of Bengkulu and Jambi, and in the east by Riau province.
85% of the population are Minangkabau, notable in the annals of anthropology as the world's largest matriarchal society: children take their names from their mother's side and, on marriage, the husband moves into the wife's family. Culturally, the hallmarks of Minangkabau culture are their famously spicy food, served all around Indonesia in Padang restaurants (named after the capital), and the soaring-eaved rumah gadang house, shaped like a series of buffalo horns.
On the other hand, the tribal inhabitants of the Mentawai archipelago, a group of islands about 100 miles off the coast of west Sumatra, cling to a traditional agrarian lifestyle that is totally different from that of Minangkabau.