Lake Trasimeno is a tectonic lake in the province of Perugia, in the Umbria region, has an area of 128 sq km, the largest lake in central Italy, fourth among the lakes in Italy immediately after Lake Como; this extension, however, is accompanied by a shallow depth (average 4.3 meters, maximum 6 meters), which makes it classified as a laminar lake.
The countryside surrounding Lake Trasimeno looks like a hilly amphitheater that frames its surface. The west coast stretches into a flat strip open towards the Val di Chiana. The north-west part of the Trasimeno area marks the border area between the province of Perugia, of which the lake is an integral part, with the neighboring provinces of Siena and Arezzo.
The lake is fed mainly by the rains and by the Rigo Maggiore, Tresa, Moiano and Maranzano streams, which flow into the artificial tributary of the Anguillara. Paganico and Pescia are the two natural tributaries of the Trasimeno.
In Lake Trasimeno there are three islands or, in order of size, Polvese, Maggiore and Minore.