Palazzo Pretorio was built in the first half of XIVth century to give a seat to the Podestà, a public office introduced in Barga by Florence government. In front of the entrance there is a loggia which keeps some evidences of these political and administrative system: coats of arms of Podestà, a column that remembers a visit of Cosimo I dei Medici and units of measurement used both in Florence and Barga.
Prisoners waiting for trial were confined in few undergrond rooms. An inventory of 1570 tells us that prison was composed by a dungeon and by two cells, accessible from the Sala del Consiglio by a trap door. During XVIIIth and XIXth centuries it has been modified: a room was kept for religious ceremonies, as the importance of spiritual help for prisoners has been established by Regolamento Generale per le carceri della Toscana.
The exhibits filling Palazzo rooms are explaned by poster and reconstructions and they are arranged following a chronological rule: fossils of vegetable and animals,mesolithic lithic tools, funeral objects from rich ligurian tombs, small etruscan statues as votive offers; then paintings, sculptures, jewellery and coroplastic examples dated back to Middle Age, Renaissance and Baroque.