The Olt (Romanian and Hungarian; German: Alt; Latin: Aluta or Alutus, Turkish: Oltu, Ancient Greek: Ἄλυτος Alytos) is a river in Romania. It is 615 km (382 mi) long, and its basin area is 24,050 km2 (9,290 sq mi). It is the longest river flowing exclusively through Romania. Its source is in the Hășmaș Mountains of the eastern Carpathian Mountains, near Bălan, rising close to the headwaters of the Mureș River. It flows through the Romanian counties Harghita, Covasna, Brașov, Sibiu, Vâlcea and Olt. The river was known as Alutus or Aluta in Roman antiquity. Olt County and the historical province of Oltenia are named after the river.