Historic villas of Castel Gandolfo.

The Papal Villas literally rise on top of the remains of the Albanum Domitiani, the vast country residence of Emperor Domitian (81-96 AD). The estate covered around fourteen square kilometres, stretching from the Via Appia to Lake Albano. The hillside was cut into three great terraces sloping toward the sea: the top level held the imperial servants' quarters and cisterns; the middle level the imperial palace and theatre; the lower level the cryptoporticus, the emperor's covered walkway, originally about three hundred metres long ([Papal Villas](https://www.villepontificie.va/it/cenni-storici/castel-gandolfo)).

The cisterns were fed by the springs of Palazzolo, on the opposite shore of the lake, through three aqueducts still partly in use today for the Papal Villa and the town. One of the terraces even held a hippodrome. The poet Juvenal called Domitian the "bald Nero".

After his death, the villa was no longer used as a permanent residence. Hadrian (117-138 AD) stayed briefly while awaiting the completion of his Tivoli villa. Marcus Aurelius took refuge there during the rebellion of 175. Under Septimius Severus (193-211 AD) the southernmost section housed the castra of his Parthian legionaries, who settled with their families: the decline had begun. The marbles were systematically reused for Albano; in the 14th century, the plunder intensified for the construction of Orvieto Cathedral ([Papal Villas](https://www.villepontificie.va/it/cenni-storici/castel-gandolfo)).

Around 1200, on the ruins of ancient Alba Longa, the Genoese Gandolfi family built a square fortress at the top of the hill: high crenellated walls and a small courtyard still visible today. The name of today's Castel Gandolfo derives from that family ([Papal Villas](https://www.villepontificie.va/it/cenni-storici/castel-gandolfo)).

In 1221 the castle passed to the Savelli, who held it with mixed fortunes for nearly three centuries ([Wikipedia — Castel Gandolfo](https://it.wikipedia.org/wiki/Castel_Gandolfo)). It was leased in 1389, destroyed in 1436 by cardinal Vitelleschi, briefly taken by Sixtus IV in 1482, returned to the Savelli in 1486, and elevated to a duchy under Sixtus V (1585-1590). In July 1596, under Clement VIII Aldobrandini (1592-1605), the Apostolic Chamber seized the fief because the Savelli had failed to honour a debt of 150,000 scudi. By consistorial decree of 27 May 1604, Castel Gandolfo was permanently incorporated into the inalienable patrimony of the Holy See.

Urban VIII Barberini (1623-1644) had loved staying in Castel Gandolfo since his years as a cardinal. He was the first Pope to spend his summers here: the first papal residency began in the spring of 1626, after the palace enlargement and refurbishment. The work was entrusted to Carlo Maderno, with sub-architects Bartolomeo Breccioli and Domenico Castelli. The Savelli fortress was absorbed into the new palace. The lake wing and the left side of today's facade up to the main portal were built ([Papal Villas](https://www.villepontificie.va/it/cenni-storici/castel-gandolfo)).

Urban VIII also laid out the Moro Garden, whose modest but well-defined design survives today, and the two tree-lined streets of the Galleria di sopra and Galleria di sotto. Alexander VII Chigi (1655-1667) completed the palace: the new facade toward the square, the seaward wing and the great gallery, the last designed and supervised by Bernini. The Apostolic Palace visible today on Piazza della Libertà is essentially the sum of these two campaigns.

In 1717, while still Auditor of the Apostolic Chamber, cardinal Camillo Cybo acquired from architect Francesco Fontana the small palace Fontana had built for himself. The cardinal then bought about three hectares of land opposite, and transformed it into a lavish garden with marbles, statues and fountains ([Papal Villas](https://www.villepontificie.va/it/cenni-storici/castel-gandolfo)).

The flaw was obvious: palace and garden were separated by the public road. Cybo planned to link them with a flyover at the piano nobile level of the garden — a project never realised. He died in 1743. His heirs sold Villa Cybo to the Duke of Bracciano Don Livio Odescalchi, and in March 1773 Clement XIV Ganganelli bought the villa for 18,000 scudi. Cybo's flyover was finally built only after 1929: the loggia connecting Villa Cybo to the Palace passes over the ancient Roman gate, more than two centuries after the cardinal's plan.

Villa Barberini sits on the central terrace of the Domitian residence. In 1628, Taddeo Barberini, nephew of Urban VIII, bought the corresponding land and vineyards; in 1631 he added the property of monsignor Scipione Visconti, including a small palace later expanded probably to a design by Bernini ([Papal Villas](https://www.villepontificie.va/it/cenni-storici/castel-gandolfo)).

The Papal Villas reached their current size with the 1929 Lateran Pacts, which brought the Barberini complex officially under the Holy See. New gardens were laid out: the most famous are the Belvedere Gardens, suspended above the Roman cryptoporticus. Since 1929, the papal complex has united three nuclei: the Moro Garden of Urban VIII, Villa Cybo of Clement XIV, and Villa Barberini of Taddeo Barberini.

In 1934, the Vatican Astronomical Observatory — the Specola — was moved from the Vatican to the Palace of Castel Gandolfo and entrusted to the Jesuit Fathers. The reason was pragmatic: the Rome region had lost the nighttime darkness needed for celestial observation ([Papal Villas](https://www.villepontificie.va/it/cenni-storici/castel-gandolfo)).

Over the decades, even the Castelli Romani sky became too bright for advanced research. In 1993, the Specola opened a satellite site at Mount Graham, Arizona, home of the Vatican Advanced Technology Telescope ([Vatican Observatory](https://www.vaticanobservatory.va/en/)). Castel Gandolfo remains the historic heart of the institution: one of the world's oldest continuous astronomical observations takes place in a 17th-century palace.

In 2023, at the request of Pope Francis, the 55 hectares of the Papal Villas were transformed into an educational project on the integral ecology of his encyclical: Borgo Laudato Si'. The main entrance is on Via Massimo D'Azeglio. The project integrates organic agriculture, teaching gardens, an olive mill, dairy and gastronomic productions, and educational programmes for schools and visitors ([Borgo Laudato Si'](https://borgolaudatosi.va/it/)).

On 5 July 2026, Pope Leo XIV returned to reside at the Papal Palace, fully restoring the tradition of papal summer residence interrupted by Francis. During papal stays, visits to the Apostolic Palace and gardens may be suspended: always check current availability at musei.vatican.va.

Papal summers in Castel Gandolfo were never simple leisure: they are the visible continuity of an idea of sovereignty that spans two thousand years, from the Palatine to Palazzo Barberini.