Lake Lucerne
Fourth largest lake in Switzerland, divided into 4 basins, surrounded by 5 cantons.
Lake Lucerne (German: Vierwaldstaettersee) lies in central Switzerland at the northern edge of the Alps and borders the cantons of Lucerne, Uri, Schwyz, Nidwalden, and Obwalden. According to Wikipedia, it covers about 113.6 km2, reaches a maximum depth of about 214 m, and sits at roughly 434 m above sea level. Its distinctive fjord-like, branching shape comes from glacially carved valleys and includes several connected basins such as Urnersee, Gersauersee, and the Lucerne basin.