The Keep of the Sant'Angelo Gate incorporates Perugia's largest medieval gate. The military structure, built in the 13th century with local sandstone, was later raised up two floors using limestone and brick.Inside the structure visitors can follow a museum itinerary that illustrates the city's urban development through the progressive expansion of its three sections of walls: Etruscan, Medieval and Renaissance.The building's multiple openings, in various positions in every direction, open up to offer amazing views of the city landscape and surrounding territory, culminating in a 360-degree view that can be enjoyed from the top of the building.