The second oldest castle in Naples after Castel dell’Ovo, Castel Capuano was named after the nearby Capuana Gate – Porta Capuana. It was built in the mid 12th century by the Norman King William I, the first monarch of the Kingdom of Naples, and it was enlarged by the Angevins. Many kings and queens lived here, including Queen Joanna II. The Parthenopean revolutionaries were also incarcerated here for a time. In the 16th century it became the Palace of Justice and a prison under the reign of the Spanish viceroy Pedro de Toledo.
Today, the building serves as municipal offices and is generally closed to the public. If you walk down Via Tribunali, you’ll see its façade and, bending the rules, you can walk into the courtyard. Castle Capuano is sometimes opened for tours during special occasions like May of the Monuments.