The most important place to learn the history of the Campi Flegrei. The Castle of Baia, located in a strategic area, allowed a very broad control of the area, preventing both the approach of enemy fleets, and any landings of troops. A guided tour of the castle, which has now become home to the Archaeological Museum of the Campi Flegrei, where there are six topographic sections respectively dedicated to Cuma, Puteoli, Rione Terra, Liternum, Bay and Misenum.