Viterbo is an ancient city an comune in the Lazio region of central Italy, the capital of the province of Viterbo. It is approximately 100 kilometers (60 mi) north of Rome on the Via Cassia, and it is surrounded by the Monti Cimini and Monti Volsini. The historic center of the city is surrounded by medieval walls, still intact, built during the 11th and 12th centuries. Entrance to the walled center of the city is through ancient gates.