Paraguay is a country in South America, bordering Argentina, Bolivia and Brazil. The Paraguay River (Spanish: Río Paraguay) divides the country into strikingly different eastern and western regions. Both the eastern region (officially called Eastern Paraguay, Paraguay Oriental, and known as the Paraneña region) and the western region (officially Western Paraguay, Paraguay Occidental, and known as the Chaco) gently slope toward and are drained into the Paraguay River, which separates and unifies the two regions. With the Paraneña region reaching southward and the Chaco extending to the north, Paraguay straddles the Tropic of Capricorn and experiences both subtropical and tropical climates.