Casina Pio IV, Renaissance building in Vatican Gardens, Vatican City

The Casina Pio IV is a Renaissance structure in the Vatican Gardens featuring mannerist elements, centered around an elliptical courtyard with a marble fountain. Two cherub sculptures riding dolphins anchor the courtyard, which is framed by arcaded galleries and refined architectural details.

Construction began in 1558 under Pope Paul IV as a modest retreat called Casina del Boschetto before Pope Pius IV hired architect Pirro Ligorio to redesign it. Work finished in 1562, and the structure took the name of the pope who oversaw its transformation into a more elaborate villa.

The interior frescoes were painted by a team of at least six painters, among them Federico Barocci, Federico Zuccari and Santi di Tito, working with assistants. Their programme, devised around the efficacy of baptism and the primacy of the papacy, was probably inspired by Cardinal Charles Borromeo, nephew of Pius IV, who planned the Accademia Noctes Vaticanae there in 1562.

Access is limited since the building now serves as headquarters for scholarly academies and is not open regularly to the public. Visits are possible by requesting ahead or booking special guided tours through the Vatican Gardens.

The frieze above the loggia carries the inscription "QVOD TIBI NON VIS ALTERI NON FECERIS" — do not do to another what you would not want done to you. The building once held some fifty ancient Roman sculptures, and its frescoes were painted by a team of at least six painters, among them Federico Barocci, Federico Zuccari and Santi di Tito.