The war reserve ammunition area at Fort McGilvray is located along the Battery Const. #293 access road to the north of the battery and consists of four concrete magazines and at least one smaller magazine of corrugated metal construction. The four large magazines are of the parabolic arch concrete igloo type common in seward, and are built into the hillside on either side of the road. Each of the concrete magazines was assigned a letter to identify it.
Two magazines of similar design were constructed to store antiaircraft ammunition at Caines Head and Rugged Island.