Formello is a town and comune in the Metropolitan City of Rome. It is located southwest of the Monti Sabatini, within the Regional Park of Veii. The communal territory is mostly composed by tuff and is intensively cultivated. The area has been settled since prehistoric times. As an Italian comune, it includes some of the archaeological sites associated with the powerful former Etruscan city of Veii, which rivalled Rome for a time, north of the village of Isola Farnese, south of Formello. Settlement in the region declined after Veii's destruction in 396 BC.