A watching brief during pipe laying for services in the castle garden identified a number of structures used in the modern period (18th-19th century) including an icehouse and several tanks for the collection and channelling of rainwater.

On the eastern sector of the hill occupied by the castle, a make up of large cobbles on a north-south alignment was exposed, delimited on one side by a compact line of cobbles. Still visible for about 5 m in length and 1.76 m in width and resting directly on the tufa bedrock, the structure is interpreted as the remains of a roadbed of pre-Renaissance date. All that stands of the medieval castle is the western part defined by two circular corner towers incorporated in the interventions to enlarge the structure, which took place at the same time as the building of the structures uncovered in the garden.

The castrum de montealto was first mentioned in 1159 in a document in which Federico I conferred privileges on the church of Turin. Indirect evidence of the presence of fortified structures dates to 1187 when the lords of Montaldo were invested with certain privileges by the bishop of Turin and incurred the obligation to build a curtain wall to protect at least half of the castle. The ditch excavated around the villa is only mentioned in 1266.