The 14,000 Twa (locally Cwa [tʃwa]) of the swamp forest north and west of Lake Tumba and between Tumba and Lake Mai-Ndombe in the west of the Congo are one of several fishing and hunter-gatherer castes living in a patron–client relationship with farming Bantu peoples across central and southern Africa. In this case the people are the Mongo, specifically the Mongo tribes known as Ntomba, Lia (Bolia), and Konda. The two castes are called Oto and Twa: The Oto are the agricultural patrons of the Twa.