The Garonne (, also , ; Occitan, Catalan, Basque, and , ; or ) is a river of southwest France and northern Spain. It flows from the central Spanish Pyrenees to the Gironde estuary at the French port of Bordeaux – a length of , of which is in Spain (Val d'Aran); the total length extends to if one includes the Gironde estuary between the river and the sea. Its basin area is , which increases to if the Dordogne River, which flows from the east and joins the Garonne at Bec d'Ambès to form the Gironde estuary, is included. Umayyad and Aquitanian forces fought the Battle of the River Garonne in 732 beside the river near present-day Bordeaux. Etymology The name derives from Garumna, a Latinized version of the Aquitanian name meaning "stony river" ("kar" relating to "stone" and "-ona" relating to "river"). Geography Sources The Garonne's headwaters are to be found in the Aran Valley in the Spanish Pyrenees, though three different locations have been proposed as the true source: the Uelh deth Garona at Plan de Beret (), the Ratera-Saboredo cirque ), or the slopes of Pic Aneto (Salterillo-Barrancs ravine according to the season). The Uelh deth Garona at above sea level has been traditionally considered as the source of the Garonne. From this point a brook (called the Beret-Garona) runs for until the bed of the main upper Garonne valley. The river runs for another until the French border at Pont de Rei, in total. The Ratera-Saboredo cirque is the head of the upper Garonne valley, and its upper lake at above sea level is the origin of the Ruda-Garona river, running for until the confluence with the Beret-Garona brook, and another until the French border at Pont del Rei, in total. At the confluence, the Ruda-Garona carries of water. The Ratera-Saboredo cirque has been pointed by many researchers as the origin of the Garonne. The third thesis holds that the river rises on the slopes of Pic Aneto at above sea level and flows by way of a sinkhole known as the Forau de Aigualluts () through the limestone of the Tuca Blanca de Pomèro and a resurgence in the Val dera Artiga above the Aran Valley in the Spanish Pyrenees. This underground route was suggested by the geologist Ramond de Carbonnières in 1787, but there was no confirmation until 1931, when caver Norbert Casteret