Beneath the semicircular arch lies the well connected to the castle's original cistern. Inside the wall, there are two hidden channels through which rainwater flowed down from the upper roofs.
It also collected water from the roof of the Keep, guiding it down via a stone arch that connects both buildings. Beneath a niche built into the thickness of the refectory wall, you will find the well that leads to this primitive reservoir. It reaches a depth of 7 metres and has a storage capacity of 240 cubic metres.