St. Bernard of Clairvaux founded the abbey in 1135 and it is a true example of Cistercian architecture. Built in a Latin cross design, it has two aisles with a nave and frescoes by Flemish artists. One of the most prominent features of the abbey is the huge lantern tower by Francesco Pecorari and there are attractive Baroque arches and a marble portal. The Grand Cloister by Bramante was added but later demolished and the exterior has fortifications that include a drawbridge. Outside are the ruins of the old cemetery, which holds the remains of Milan’s most powerful 13th Century families.