From 1643 to 1654, cardinal Altieri exalted its beauty by expanding and enriching the gardens with magnificent and imaginative water features, buildings and fountains designed by the architect Ludwig Gattelli with daring works of hydraulic engineering. The courtyard has porches on two sides, a loggia with stucco decorations and a magnificent balcony on large corbels, which opens onto the garden. Under the balcony stands the fountain of the episcopal palace. The palace houses a gallery with Roman school frescoes depicting biblical scenes.

Currently the Palazzo is the seat of the congregation “Ancelle dell’Amore Misericordioso" and it can be visited on request. The congregation hosts the Hope Center, a rehabilitation service for children, teenagers and adults with neuropsychological disabilities. Over the last twenty years, the Palazzo has undergone structural changes in order to make it suitable, in accordance with applicable laws.