Leonardo's prisons are adjacent to the parliamentary building, located behind it and located on the same plot. It is a three-storey heavy, stone-built, arched arcade building that was erected in the years of the 2nd Ottoman domination.
Its masonry is laid in the late 18th and early 19th century. Each floor consists of an arc of low arches on heavy pillars, which is limited to the edges by a tower protrusion. The arches of the ground floor are higher than those on the other floors.
In this building, two building phases are distinguished. At the first, the central section with the three galleries and the side ground floor sections were constructed, while at a later stage the upper part of the towers and the entire rear view were made.
In this new phase no chiselled isometric stones (as in the first) were used but small raw stones mixed with ceramides. The elbows in the windows are made of porosity. The union of the two dissimilar modes of construction is easily perceived in the corners where the galleries end.
At first it is most likely that the building was used as a Turkish mercenary (Turkish Teaching School). Since 1926 he has been turned into jail when the Palamidi prisons have been abolished. But as it appears after the release, he must maintain the same use, since Staikopoulos died in the prison of Leonard.
Today, the Archaeological Service houses the workshops for the welding of vessels. Generally the building is in good condition without any special alterations.