Papal Palace of Castel Gandolfo site features

The Papal Palace of Castel Gandolfo -- the Palazzo Apostolico di Castel Gandolfo -- is not one building but a complex of 54.6 hectares in a garden setting above Lake Albano: the principal seventeenth-century villa, an observatory, and a farmhouse with 30.4 hectares of farmland. Carlo Maderno, the Swiss-Italian architect who finished St Peter's, designed the palace for Urban VIII, who began using it in the spring of 1626.

The estate

The gardens occupy the site of a residence of the emperor Domitian, so the papal summer retreat sits on an imperial one. The adjoining Villa Barberini was added to the complex by Pius XI, and its own Barberini Gardens are the part the Vatican opened first, to paid escorted tours from March 2014. John Paul II had a swimming pool built here, which drew both criticism and paparazzi. The farm's produce was for Vatican employees only until late 2015, when it went on public sale.

What is sold as a visit

The Vatican Museums run the site as the Polo Museale di Castel Gandolfo and sell it as the Palazzo Papale together with the Giardino Segreto -- the secret garden. The palace itself was opened to the public on 21 October 2016 without any structural changes being made to it, which is what allowed it to be handed back as a residence a decade later.

Legal status

Under the Lateran Treaty of 1929 the palace is Italian territory but owned by the Holy See, with extraterritoriality comparable to that of a diplomatic mission. It is exempt from Italian taxes and from expropriation, and Italian authorities may not enter it without the consent of the Holy See.

The Giardino Segreto

The secret garden, sold by the Vatican Museums together with the Palazzo Papale as a single visit. The Barberini Gardens next door were the first part of the estate opened to paid escorted tours, from March 2014.

Domitian's ground

The gardens occupy the site of a residence of the emperor Domitian. The papal summer retreat is on top of an imperial one.

The observatory

One of the three principal elements of the 54.6-hectare complex, alongside the villa and the farmhouse -- the Church's astronomy on the same estate as its holidays.

The farm

A farmhouse with 30.4 hectares of farmland, more than half the estate. Its produce was available only to Vatican employees until the end of 2015, when it was put on public sale.

The papal train

From 11 September 2015 the public has been able to travel from Vatican City to Castel Gandolfo on a train previously reserved for the pope.

Two papal deaths

Pius XII died at the palace in 1958 and Paul VI in 1978. Benedict XVI flew here at the conclusion of his papacy on 28 February 2013, was joined by Francis for lunch on 23 March, and returned to Vatican City on 2 May.

An extraterritorial boundary

Italian territory owned by the Holy See, exempt from Italian taxes and expropriation, which Italian authorities may not enter without the Holy See's consent. The gate is a legal threshold.