There are lakes and then there are huge lakes. What struck me as odd were the sizes of these
Swiss lakes. It was funny, as the German word for lake is see. These are really as huge as seas.

Some big lakes in Switzerland

Lake Geneva (Lac Léman, Lac de Genève) - 581.3 km²
Lake Constance (Bodensee) - 541.1 km²
Lake Neuchâtel (Lac de Neuchâtel) - 218.3 km²
Lago Maggiore - 212.3 km²
Lake Lucerne (Vierwaldstättersee) - 113.7 km²

Links and info for all lakes can be found here...