Lake Como is in the southern sector surrounded by limestone hills, such as the Grigne range while in the northern part dominate schist and gneis-mountains, like Mount Legnone (2609m).
You can see the deeply eroded valleys carved out by the glaciers and torrential waters. The Alpine peaks and glaciers in the north, several picturesque lakes, and upland pastures that slope to the rich, irrigated Po valley in the south. The Valtellina valley is in the northeast. The River Adda flows into the lake near Colico and flows out at Lecco. Unfortunately as there is no outlet for the river at Como, this town is prone to flooding in bad weather.