The Rhone is one of the major rivers of Europe, rising in Switzerland and running from there through southeastern France. At Arles, near its mouth on the Mediterranean Sea, the river divides into two branches, known as the Great Rhone and the Little Rhone. The resulting delta constitutes the Camargue region. In French, the adjective derived from the river is rhodanien, as in le sillon rhodanien (literally "the furrow of the Rhone"), which is the name of the long, straight Saône and Rhone river valleys, a deep cleft running due south to the Mediterranean and separating the Alps from the Massif Central.
Before railroads and highways were developed, the Rhone was an important inland trade and transportation route, connecting the cities of Arles, Avignon, Valence, Vienne and Lyon to the Mediterranean ports of Fos, Marseille and Sète. Travelling down the Rhone by barge would take three weeks. By motorized vessel, the trip now takes only three days.
The Rhône is classified as a class V waterway from the mouth of the Saône to the sea. The Saône, which is also canalized, connects the Rhône ports to the cities of Villefranche-sur-Saône, Mâcon and Chalon-sur-Saône. Smaller vessels (up to CEMT class I) can travel further northwest, north and northeast via the Centre-Loire-Briare and Loing Canals to the Seine, via the Canal de la Marne à la Saône (recently often called the "Canal entre Champagne et Bourgogne") to the Marne, via the Canal des Vosges (formerly called the "Canal de l'Est - Branche Sud") to the Moselle and via the Canal du Rhône au Rhin to the Rhine.
The Rhone is infamous for its strong current when the river carries large quantities of water: current speeds up to 10 kilometres per hour (6 mph) are sometimes reached, particularly in the stretch below the last lock at Valabrègues and in some of the diversion canals. The ten river locks are operated daily from 05:00 a.m. until 09:00 p.m. Night operation can be requested and is usually granted.