The Papal Palace of Castel Gandolfo, or the Apostolic Palace of Castel Gandolfo from its Italian name Palazzo Apostolico di Castel Gandolfo, is a 135-acre complex of buildings in a garden setting in the city of Castel Gandolfo, Italy, including the principal 17th-century villa, an observatory and a farmhouse with 75 acres of farmland. Wikipedia