Due to safety concerns, explosive materials were stored outside the castle and not inside. After the Gunpowder Tower lost its roof in the 19th century, part of the building collapsed into the outer moat in the 1930s. Today, only remnants of the wall are visible.

The remains of the building next to the Gunpowder Tower were probably magazines.

Most magazines were above-ground piles of dirt with hollowed-out interior spaces for storing powder and artillery shells. If well situated, magazines protected the dangerous ordnance from moisture, from clumsy soldiers, and from incoming enemy fire.