Entering via the drawbridge and main entrance one has direct access to the interior of the bulwark, which houses the tower's artillery, placed at 17 cannon holes. The floor slopes downward from the centre outwards, giving the artillery a secure position and allowing for the runoff of water that enters the tower.
In the centre there is a small, cloister-like, open patio, surrounded by Gothic arches. This helped disperse the smoke when the cannons were fired.
Under the nave of the bulwark there are a number of magazines, the largest of which is accessed via a stairway on the north side. These magazines were originally intended as storage rooms for provisions but they were later used as dungeons.
On the right, as one moves through the entrance hall, there is also a steep staircase that leads to the bulwark terrace.