Trasimeno Lake ( Italian : Lago Trasimeno ; Latin : Trasumennus ; Etruscan TarÅ›mina [ 1 ] ), also referred to as Trasimene or Thrasimene in English, is the largest lake on the Italian peninsula south of the Po River with a surface area of 128 km 2 , slightly less than Lake Como . No major river flows directly into or out of Lake Trasimeno and the water level fluctuates significantly according to rainfall levels and the seasonal demands from the towns, villages and farms near the shore. Trasimeno is shallow, muddy, rich in fish, including pike, carp, and tench. It is 4 meters deep on average. Lake Trasimeno is an endorheic body of water; it is an impounded lake that receives water but has no outlet. Other endorheic bodies of water include the Caspian Sea , Aral Sea , Utah’s Great Salt Lake , and the Dead Sea . Evaporation can lead to a build up of minerals in the water, resulting in a saline conditions, making these lakes sensitive to pressures from pollution. Three million years ago, there was a shallow sea in this part of Umbria. A depression formed by geologic fractures allowed the present-day Lake Trasimeno to form.
Historically, Trasimeno was known as The Lake of Perugia , being important for northwestern Umbria and for the Tuscan Chiana district. In prehistoric times, this lake extended almost to Perugia. Trasimeno is a mythological figure, joined with Agilla, a nymph born in Agello, now a hill midway between Perugia and Trasimeno, formerly an island in the lake.
There are three islands in the lake. The largest of these islands is Isola Polvese , almost 1 km 2 . The second largest, Isola Maggiore , is the only inhabited one. The small fishing village, which reached its height in the 14th century, today has only around thirty residents. Most of the buildings, including the ruins of a Franciscan monastery, date from the 14th century. (from Wikipedia)