Castel Gandolfo, colloquially known as Castello in the Castelli Romani dialects, is a town located 25 km (16 mi) southeast of Rome, in the Italian region of Lazio. Situated on a hilltop in the Alban Hills with panoramic views of Lake Albano, Castel Gandolfo is home to approximately 8,900 residents and is renowned as one of Italy's most scenic towns. It is one of I Borghi più belli d'Italia.

Lake Albano is a small volcanic crater lake in the Alban Hills of Lazio, at the foot of Monte Cavo, 20 km (12 mi) southeast of Rome. Castel Gandolfo, overlooking the lake, is the site of the Papal Palace of Castel Gandolfo.