Castel Nuovo (Italian: "New Castle"), often called Maschio Angioino, is a medieval castle located in front of Piazza Municipio and the city hall (Palazzo San Giacomo) in central Naples, Italy. Its scenic location and imposing size makes the castle, first erected in 1279, one of the main architectural landmarks of the city.

The imposing single-sided white marble triumphal arch, built in 1470, commemorates Alfonso of Aragon's entry to Naples in 1443. It stands between two western Towers of the Angevin castle. The overall design had been attributed to Pietro di Martina, a Milanese architect, or, according to Vasari, to Giuliano da Maiano. Modern authors attribute the design to Francesco Laurana.

https://en.wikipedia.org/wiki/Castel_Nuovo