Introduction to the Tarn River: The Tarn River is a river in southwestern France, with a total length of 375 kilometers. The river water originates from the south side of the Lozere Mountains in the Central Plateau, flows into the Garonne River in the Tarn-Garonne department, and flows through May. The spectacular valleys of the Mejean and Sauveterre hills are 48 kilometers long and are one of France's most famous tourist destinations. After entering the Aquitaine lowlands and passing through Albi, the capital of the Tarn department, the river joins the important tributary Aveyron downstream of Montauban.