Palazzo della Ragione, Mantua

It was joined to Palazzo del Podestà by Gonzaga family; when a blaze destroyed Palazzo del Podestà in 1413, it became Palatium Juris, id est the courthouse. Years later, the porch giving onto piazza Erbe and the Torre dell'Orologio - id est the clocktower – were added.
It is one of the buildings the Commune built in XIII century; not only it was a courthouse, but it also hosted several shops on the ground floor. Some late XIII century frescoes deck the main hall, depicting sacred scenes, a comet, and some sea and military scenes.
You can reach the main hall even entering the clocktower by Luca Fancelli (1473); the wonderful astronomic clock was made in late XV century by Bartolomeo Manfredi.