Le mura di Pisa ( da Mura di Pisa, www.muradipisa.it)
The medieval walls of Pisa
Veduta di Piazza del Duomo da Porta Nuova (G. Bettini, Comune di Pisa)It is not certain that Pisa had walls from the Etruscan, Roman, or even Lombard period. The geographical position, on the confluence of the Arno and Auser rivers (today Serchio), the dense network of canals and the marshy terrain gave it a certain natural protection. For sure there were fortresses and towers in strategic places, but the descent of Frederick Barbarossa in 1154, interested in knowing a city that declared itself to be free, was decisive for the construction of the new walls. In the same year, Consul Cocco Griffi started the construction of the Pisa walls, starting right from Piazza del Duomo, near the Leone gate. 11 meters high, up to 2 meters thick, they were completed in a century, with a Roman-stylemasonry technique, and using a variety of materials: tuff, limestone from the nearby town of San Giuliano and Verrucana stone. The entire perimeter measured about 7 km, with towers every 300 meters and about 20 gates; the enclosed surface was almost 200 hectares. Today a little more than 5 km of walls remain standing, given the nineteenth-century demolitions and war destruction, and it is possible to walk on top of about 3 km of them.
