How did the sunken profile protect a fortress from artillery bombardment?

The sunken profile protected a fortress from artillery bombardment by lowering the main fortress walls, or scarp, into the ground behind a ditch. This design shielded the walls from direct enemy fire by placing them behind a glacis—a gradually sloping earthen rampart that rose in front of the ditch.1

By positioning the main defensive walls below the level of the surrounding terrain, the structure became significantly harder for attackers to target with artillery. The glacis served as a protective barrier that forced incoming fire to strike the earth rather than the vulnerable masonry of the fortress walls. Additionally, this configuration allowed defenders to maintain a parapet behind the ditch, from which they could sweep the glacis with their own cannon and harquebus fire, effectively controlling the approach to the fortification.1