The building that now houses the command of the Third Army Corps was built in the late 19th century by the then Ottoman government, to be used as a barracks. It was designed by the Italian architect Vitaliano Poselli, who had settled in Thessaloniki and designed many - mostly public - buildings of the city at the request of the Ottomans. After the liberation, the building was handed over to the Greek army, while in 1916 it housed the provisional government of Eleftherios Venizelos.
It is a two-storey, elongated building, in a rectangular shape, which lines the chambers symmetrically inside, along a large corridor. Its entrance is accentuated by a ledge, porch, and gable at the end, while its entire external appearance is characterized by symmetry on the vertical and horizontal axis with visible global ones, which are also observed internally.