Rocca Farnese (or Palazzo) is the oldest surviving residence of the Farnese family and, with its 16th-century bulk, dominates the historic centre of Ischia di Castro, a town in the Maremma Laziale and Tuscia Viterbese area. Ischia is one of the oldest lands of the Farnese family, from where they began their military, political and cultural expansion.

Over the centuries, architecture and the arts have been among the instruments of their rise: just think of Palazzo Farnese in Rome, the Farnese Theatre in Parma and the Farnese archaeological and pictorial collections in Naples.

The Rocca was built from the 13th century as a fortification around a pre-existing tower of the Aldobrandeschi family, then enlarged in the form of a palace in the early 16th century according to a design never completed by Antonio da Sangallo the Younger.

Ischia was part of the Duchy of Castro, the sovereign state of the Farnese family on the border between the States of the Church and the Grand Duchy of Tuscany. In 1527, Pierluigi Farnese, son of Pope Paul III, signed a letter written on behalf of Emperor Charles V “from my palace in Ischia”.
From the end of the duchy in 1649, the palace passed to the Camera Apostolica, then to the Capranica family and then to the Piermartini family.
Antonio Canova was appointed Marquis of Ischia by Pius VII.
The current owner, art historian Stefano Aluffi Pentini, bought it in 2008 and immediately undertook its restoration.