The Sannez courses northward from the Pale Sisters, supplemented by the numerous spring-fed streams of the region. Couronne's famous hot-springs and mineral waters join the Sannez and swell its bulk considerably below the city and no doubt are an important contributor to the valley's remarkable fertility. From Couronne to the sea, the Sannez is fully navigable to ocean-going vessels - even though it meanders round in a great arc from north to south and finally flows westward into the Middle Sea - and the gentle hills that surround its banks provide ample cargoes in the form of local wine. At the coast, the river flows through the huge port of L'Anguille, with its famous 1,500-foot high light-tower.