The Cosia is a 16 kilometres (9.9 mi) torrent whose springs are on the slopes of Monte Bolletone in Brianza, Italy. Its course takes it through the communities of Albese con Cassano, Tavernerio and Como, then it enters Lake Como near the war memorial designed by Antonio Sant'Elia and executed by Giuseppe Terragni. The river has two tributaries: the Valloni on the left and the Tisone on the right.