The Castle of Charles V (Italian: Castello Carlo quinto; Leccese: Castellu Carlu Quintu), also known as the Castello di Lecce, is a castle in Lecce, Italy. It was first built in the Middle Ages, and was strengthened by Charles V in 1539, to a design by the architect Gian Giacomo dell’Acaya. To build this fortress two constructions were pulled down: the Chapel of the Trinity and the Monastery of the Benedictine Order of the Saint Cross.