The lake of Como (or Lario) is the first Italian lake for its perimeter, the third one as surface and the fifth deepest basin of Europe with its 410 meters after 4 Norwegian lakes. Entirely dug in the Lombardy prealpis, with a characteristic form to inverted "Y", in the period after the glaciation the alluvial deposits, transported by rivers and streams, separated and formed the smaller lakes: in the north the lake of Mezzola and in the south the lakes of Garlate and of Olginate. The basin is composed by three different parts: in the south-west the Como coast, in the south-east the Lecco coast and to north the branch of Colic. There is only one island on the lake, the island Comacina, that had notable importance during the war between the Municipality of Como and Milan.