The powder magazines were an important part of the facilities that should contain everything necessary to withstand a long siege by enemy forces: water, food, weapons, ammunition and gunpowder. In this case they are built under cover of gunfire from the enemy, on the north wall of the castle, between the main wall and the barracks in a place of particular charm.

Its interior is coated with a particular type of porous stone that absorbs moisture and maintains a stable temperature for the proper conservation of gunpowder, a rear ventilation chamber provides this function and possibly prevent the destruction of the outer wall in case of accidental explosion.