This structure, now used as a beach house, was completed in September 1943 on a government-owned 1.41 acre site as a Base-End Station for Fort Dearborn and Fort Foster. The second story observation level was intended for Battery 205 (B6 S6), and the first story level was for Battery Seaman (B11 S11). The roof, through a trap-door, was used as the anti-aircraft intelligence station (AAIS OP 10). The attached cottage as shown was somewhat modified from the original design. Searchlight positions #17 and #18 were located east of the tower on the shoreline. A seperate fire-control switchboard building, disguised as a one-car garage, was located to the rear of the house. It was later converted to the real thing.