The Rhône borders the city of Avignon to the west and marks the frontier between the Vaucluse and Gard departments. Five hundred and four miles (812 km) long, it crosses part of Switzerland before joining France and flowing south from Lyon, between the Alps and the Massif Central. The Rhône then receives the waters of the Isère, Drôme, Ardèche, and Ouvèze before crossing the city of Avignon downstream from which it is joined by the Durance. At Avignon, it is divided into two arms separated by a string of islands, including the large island of Barthelasse (photo). The arm bathing Avignon to the east is called the Petit Rhône or dead arm, while the one running along Villeneuve-lez-Avignon to the west is the Grand Rhône or lively arm.