Defending the high ground rather than every shoreline

The proposed fortification scheme puts the decisive artillery and protected works in the upper town. The lower town contains the population and harbour and would receive some protection, but it need not absorb most of the construction effort. An attacker confined below the cliffs could be contained or subjected to fire until naval reinforcements arrived. The defenders would also protect stores and prevent an enemy from establishing artillery on the neighbouring dune. Holding the heights, rather than every stretch of shoreline, is the core of the scheme.