The first lazaretto of the island had been constructed soon after the foundation of the new town (Hermoupolis) and was situated at the place where actually is located the Shipyard (“Neorio”). The building had been designed by Lambros Zavos. Within a short period of time it was proved that the construction could not cover the increasing needs of the rapidly developing town and the Bavarian regents decided to construct a new one. The realization of the project was entrusted to the architect J. Erlacher, but for various reasons his designs were never realized. In 1837 it was decided anew that a new lazaretto should be constructed. This time the project was entrusted to Weiler who designed the new building which was constructed in the years 1839-1841, at the site of “Pedali”, under the supervision of Lambros Zavos and with public financing.
The complex was quite imposing and surrounded a rectangular courtyard whose entrance was situated at the southern side, where today the visitor can see the foundation stone made of marble. On three sides of the building there were 32 apartments who served as residencies of the travelers obliged to stay there for a few days until they were allowed free access to the island. The apartments had a separate entrance at the north. The buildings of the western part housed the kitchens and the administrative services. The main forefront of the building faced the sea and was symmetrical, with one storey at the middle and two – storeyed at its ends. It had dry-stone wall base and the upper walls were made of rectangular stones. The upper part had arched openings with frames made of marble and red bricks and other decorative architectural feature. The internal face of the main side had characteristic double-arched openings with red bricks at the upper part, based on columns made of porous stone. All 32 apartments had a separate kitchen, lavatories and fireplace for heat. Most of the travelers arriving from Asia Minor and the European part of the Ottoman Empire were obliged to stay in the lazaretto for at least seven days.
Later on, by mid 19th century the practice of staying in the lazaretto as a measure of precaution against plagues was gradually abandoned. As a result the building was deserted. At the end of the 19th century the complex started to operate again, this time as a prison, a use that continued until the postwar period. In 1908 the Lazaretta housed the “Asylum for the Insane People”, which had been established by the Philanthropic Committee of Hermoupolis.
After the civil war in Greece, at the prison of Lazaretta there were often detained for a while the political prisoners, before transferring them at the uninhabited island of Gyaros. As the building did not cover the needs, it underwent modifications which changed the courtyard and destroyed a part of the original building; these modifications completed the ones caused in the years before, due to the abandonment of the building and the extensive extraction of building material. A two-storey building beside the beach, below the Lazaretta is dated in the same period. Later on, this building was used by the company of “Eastern” and ever since was known as the “Telegraph Office”.
Nowadays the complex is a property of the Municipality of Hermoupolis which plans a renovation and restoration of it, in order to house various services and amenities, probably the Casino of the town.