The Rocca del Leone is an interesting structure irregular pentagonal, dominated by a triangular tower high 39 meters; the corners, four towers strengthen the crenellated walls. The fortress was erected by the emperor Frederick II of Swabia in the early decades of 1200, as an objective in the displacement of the troops, on the remains of a more ancient building, accompanied by a parish church dedicated to the Saints Filippo and Giacomo, of which remain only a few ruins. The true fortress is constituted by the extreme appendix of the bulwark that tightens the small peninsula on the Trasimeno. The male exercised activity of accurate surveillance on the lake and on the neighboring lands, representing the last fortification of precaution. The Ducal Palace is in communication with the fort through a suggestive covered walkway (with slits on the lake) for which it is approached from a port located in the hall of the throne. It is currently used for folkloristic shows and theatrical performances during the summer.