The Circuito Sur de Oriente (CSO), meaning Southern Circuit of the Orient, is a west-east highway connecting Bayamo to Santiago de Cuba, through Manzanillo, Niquero and the southern coastal side of eastern Cuba, below the Sierra Maestra mountain range. Also known as Circuito Guacanayabo-Sur de Oriente, because it crosses the Gulf of Guacanayabo, the name Oriente (meaning Orient), refers to the ancient and former Oriente Province. With a length of 347 km, it is the fourth-longest Cuban highway after the Carretera Central, the Circuito Norte and the Circuito Sur.