lake in Lombardia (Lombardy) region, northern Italy, between Bergamo and Brescia provinces, at the southern foot of the Alps at an altitude of 610 feet (186 m). The lake is 15.5 miles (25 km) long with a maximum width of 3 miles (5 km), a maximum depth of 820 feet (250 m), and a surface area of 24 square miles (62 square km). It is fed by the Oglio River, a tributary of the Po River, which enters the northern end near Lovere from the deep, wide Val (valley) Camonica and leaves the southern end at Sarnico. Monte Isola, in the centre of the lake, is Italy's largest lacustrine island (area 5 square miles 【13 square km】); it rises to 1,965 feet (599 m) and is crowned by a chapel. The islet of San Paolo, south of Monte Isola, is occupied by the buildings of a small disused Franciscan convent, and that of Loreto, north, has a ruined chapel containing frescoes.

Olives, vines, and fruits are grown on the lake's shores. Iseo, at the southern end of the lake, is a summer resort.