Castel Nuovo, also known as the Maschio Angioino, is a medieval castle in the city of Naples, Italy. It was built in 1279 by Charles I of Anjou, the King of Naples. The castle was strategically positioned to control the city's port, and it served as a residence for the Angevin monarchs until the Aragonese conquered Naples in the 15th century.

The castle has undergone several transformations throughout the centuries. In the 15th century, the Aragonese built a triumphal arch and a new entrance to the castle. In the 16th century, the castle was renovated to serve as a residence for Spanish viceroys. During this time, the castle's interior was decorated with frescoes and artwork.

The castle is a large and impressive structure, with a moat, towers, and battlements. It is surrounded by a large park known as the Piazza del Plebiscito, which is a popular gathering place for locals and tourists. The castle also houses the Museum of Naples, which features a collection of medieval and Renaissance art and artifacts.