Lake Geneva is divided into three parts because of its different forms of formation (sedimentation, tectonic folding, glacial erosion): According to the Swiss Federal Office of Topography, swisstopo, "Lac de Genève" designates that part of the "Petit Lac", which lies within the cantonal borders of Geneva (excluding the cantonal exclave Céligny), so about from Versoix–Hermance to the Rhône outflow in Geneva. The Chablais Alps border is its southern shore, the western Bernese Alps lie over its eastern side. The high summits of Grand Combin and Mont Blanc are visible from some places. Compagnie Générale de Navigation sur le lac Léman (CGN) operates
Lake Geneva than in Geneva. In 563, according to the writings of Gregory of Tours and Marius Aventicensis, a tsunami wave swept along the lake, destroying the fort of Tauredunum and other settlements, and causing numerous deaths in Geneva. Simulations indicate that the Tauredunum event was most likely caused by a massive landslide near the Rhône delta, which caused a wave eight meters high to reach Geneva within 70 minutes. In 888 the town was part of the new Kingdom of Burgundy, and, with it, was absorbed into the Holy Roman Empire in 1033. In the late 1960s, pollution made it dangerous