A lazzaretto is a quarantine station for maritime travellers. Passengers arriving on board ships from infected countries had to spend a number of days (usually around forty) in quarantine before being allowed to mingle with the inhabitants. This was done so as to ensure that any symptoms of the disease would be manifested and, as a result of this preventive measure, the infection would not be spread to the rest of the population.
The first lazzaretto was set up on Manoel Island in 1592 during an outbreak of the plague. At that time, temprary wooden huts were set up. These were later demolished. In 1643, Grand Master Lascaris, built a permanent structure in the same place to control the periodic outbreaks of plague and cholera on board visiting ships. The building consists of two floors with eight rooms on each floor surrounding a central courtyard. A series of arches runs along the facade facing the sea. Persons who died in the lazzaretto were buried on Manoel Island in one of six cemeteries that existed there at different times.
Additional buldings were added from time to time, depending on the exigencies of the moment. In 1670, Grand Master Nicholas Cotoner made some improvements on the building constructed by Lascaris. Stores and warehosues were erected to house merchandise from infected ports, together with facilities for disinfection and fumigation. The lazzaretto was enlarged further between 1837-38 under the governship of Sir Henry Frederick Bouverie.
Some famous visitors kept in isolation in the lazzaretto on Manoel Island were Lord Byron, Sir Walter Scott, William Thackeray, the Reverend (later Cardinal) John Henry Newman and a young Benjamin Disraeli.
The lazzaretto on Manoel island was used as recently as 1937 when there was an outbreak of the plague. During WW2 it was damaged and eventually fell into a state of disrepair. In spite of plans to restore it, it is still an abandoned shell, slowly crumbling into the sea.