The Bishop's Palace houses some frescoes by Baldassarre Peruzzi. They were brought to light by Father Geremia Sangiorgi in 1977, then parish priest of Ostia Antica. The reason why they were covered up is to be found in the great plagues of the past (the Episcopio may have been used as a lazaret, for quarantine, as evidenced by the clear signs on the walls) and in the "sanitary" disposition of the time that wanted everything covered with quicklime. This is why the frescoes remained buried for centuries.