The Lazzaretto was a place for the quarantine of sailors to prevent the spread of infectious diseases. It is located between the city parts of Mlaka and Potok. It was situated on the sea itself with a small harbour, a stream flowing into it on the east side and a bridge over itconnecting the Lazzaretto wharf with the shore towards Rijeka. The central part of the southern front of the complex was occupied by the building of the priory, originally made in the layout of the letter "L". A tower with a loggia for a bell and a clock rose from the central part of the building. The space between the two ends of the priory formed a courtyard surrounded by a wall and was connected to the harbour by a driveway through a door. To the west of the priory there is a long building perpendicular to the shore that served as a warehouse for the Lazzaretto. Between the warehouse and the priory there is an entrance vault with a donor inscription. A barn was located in the northwest corner and the entire complex was enclosed by a wall. On the north side there was another entrance to the Lazzaretto. The northeastern part of the complex was completely separated from the rest of the Lazzaretto and the outside world and was intended for accommodation. To the north of the buildings there was the Lazzaretto cemetery. Inside the complex there was the chapel of St. Charles Borromeo, who is also the patron saint of the Rijeka Lazzaretto.