Lake Trasimeno, also referred to as Trasimene or Thrasimene in English, is a lake in the province of Perugia, in the Umbria region of Italy on the border with Tuscany. The lake is south of the river Po and north of the nearby river Tiber, has a surface area of 128 km² and is the fourth for surface area in Italy. Only two minor streams flow directly into the Lake and none flows out. The water level of the lake fluctuates significantly according to rainfall levels and the seasonal demands from the towns, villages and farms near the shore.