The facade, designed by G.S. Peruzzi, is built in travertine pilfered from the Colosseum. It has two stories. The lower is divided into five parts, and the upper into three with volutes above the outer parts of the lower level. There are three doors, a large one in the middle, and two smaller adjacent to it with windows above them. The outher parts have large windows. On the upper level, there is a large window in the middle and slightly smaller windows on the sides. It is crowned by a triangular tympanon.