Castellnovo Castle, the Palace of Beatriz de Borgia, occupies 520 square meters atop San Cristóbal hill at 380 meters elevation in the province of Castellón. The fortress reached its zenith in the mid-15th century under Beatriz de Borgia, sister of future Pope Alexander VI and niece of Pope Calixtus III, who became Baroness after marrying Ximén Pérez d'Arenós. Beatriz transformed the medieval fortress into a Renaissance palace showcasing wealth and power through elegant architectural elements including vaults, pointed arches, and machicolation at the main entrance, making it one of Spain's earliest Renaissance examples in Valencia. The castle's origins are believed to be Roman, part of Segorbe's defensive network, and it was subsequently rebuilt during Muslim occupation, which inspired its name meaning 'new castle.' This palimpsest of architectural styles reflects centuries of Iberian cultural transformation.
