It was constructed by Azzone Visconti in 1335 and was completed in 1372 under Galeazzo II. The Castle follows a four-sided plan with an internal courtyard surrounded by a portico with pointed arches and square angular towers plus another two middle towers on the north and south face of the Castle. This is one of the most important Visconti castles in Pavia; however it has fallen into a severe state of disrepair over the centuries and since the Napoleon era to date, was used as the Voghera jail. Although abandoned, it is now undergoing restoration works.