Entry ticket that includes access to the museum spaces and temporary exhibitions, the two towers, and the ramparts.
Over the course of its thousand-year history, the hill on which Castel Grande stands has witnessed numerous phases of settlement, construction, and control: evidence of this includes Neolithic settlements from the 6th millennium BC, Roman garrisons, the first fortifications from the 4th century AD, the presence of the Lombards and the Franks between the 6th and 8th centuries, and the residence of the Bishop of Como during the high Middle Ages.

However, the fortified complex that can be seen today dates back to the late medieval period, specifically between the 13th century and the end of the 15th century.

The southern buildings of the castle, now home to the Historical and Archaeological Museum, were an area of paramount importance as the site of the military garrison. In times of peace, the castle's castellan was stationed there, accompanied by at least twenty infantrymen tasked with guarding the castle. Often serving as a station for garrisons sent to Bellinzona in times of war, Castel Grande was intended to be an impenetrable stronghold: only those who presented a document bearing the ducal seal were allowed to enter the perimeter of the fortified complex.