Lake Geneva is the largest body of water in Switzerland, and greatly exceeds in size all others that are connected with the main valleys of the Alps. It is in the shape of a crescent, with the horns pointing south, the northern shore being 95 km (59 mi), the southern shore 72 km (45 mi) in length. The crescent form was more regular in a recent geological period, when the lake extended to Bex, about 18 km (11 mi) south of Villeneuve. The detritus of the Rhone has filled up this portion of the bed of the lake, and it appears that within the historical period the waters extended about 2 km (1.2 mi) beyond the present eastern margin of the lake. The greatest depth of the lake, in the broad portion between Evian and Lausanne, where it is just 13 km (8.1 mi) in width, has been measured as 310 m (1,020 ft), putting the bottom of the lake at 62 m (203 ft) above sea level. The lake's surface is the lowest point of the cantons of Valais and Vaud.
The beauty of the shores of the lake and of the sites of many of the places near its banks has long been celebrated. However it is only from the eastern end of the lake, between Vevey and Villeneuve, that the scenery assumes an Alpine character. On the south side the mountains of Savoy and Valais are for the most part rugged and sombre, while those of the northern shore fall in gentle vine-covered slopes, thickly set with villages and castles.