Designed by Luigi Vanvitelli, the building is situated on a pentagonal artificial island located within the port and connected to the mainland by three bridges. Originally it could only be reached by sea and its water supply was done by means of three wells located in small Neoclassical temple dedicated to St. Rocco. The temple is open on all four sides, it allowed the detainees to overlook the courtyard and attend mass. On the inside of the building are the premises of Lazzaretto intended for quarantine, while the rooms in the outer part were used as storage to confirm multi-functionality of the structure.