Ferrara: Palazzo dei Diamanti (Palace of Diamonds); built 1493 - 1503; detail of facade; This Renaissance style palace was built for Sigismondo d`Este; brother of Duke Ercole I; by architect Biagio Rossetti; who also did the city extension called Addizione Erculea; from 1492 onwards. The palace is located at the crossing Quadrivio degli Angeli; the centre of the Addizione Erculea. Most important are the exterior walls (facades) of the palace; built in a technique called bugnato (bossage). The facades consists of c. 8;500 white marble blocks shaped in form of diamonds. The further decorations at the facades are attributed to Gabriele Frisoni from city of Mantova and to Gaetano Davia from Ferrara. The palace houses the Pinacoteca Nazionale di Ferrara (National Picture Gallery of Ferrara) and the Civic Gallery of Modern and Contemporary Art.