The fifteenth-century palace built by Cardinal Rodrigo Borgia — the future Pope Alexander VI — directly opposite Palazzo Piccolomini across the cathedral piazza. It now houses the small but unusually rich Diocesan Museum.
The collection has medieval gold-ground panel paintings by Pietro Lorenzetti and Bartolo di Fredi, an extraordinary fourteenth-century English cope (the "Piviale di Pio II") embroidered with the lives of saints, and a fragment of a tapestry that belonged to the pope himself. The museum is rarely crowded and a useful way to spend an hour in Pienza out of the sun.