Tucked beside the cathedral, this small 18th-century oratory is easy to miss but worth seeking out. Tiepolo's ceiling fresco of the Assumption of the Virgin, painted in 1759, is one of his most luminous late works. His son Giandomenico contributed monochrome scenes from the Old Testament around the walls.
The oratory is normally closed; ask in the cathedral sacristy for access. It is a quick, rewarding addition to the cathedral visit.