During the Second World War, Mount Martha's Balcombe Creek camp hosted the United States Marine Corps's 1st Marine Division in late 1942 following their involvement in the Battle of Guadalcanal. After the conclusion of the war, it was progressively relocated or demolished until 1999. The area is now known as Balcombe Estuary and has barbecue facilities (including an open fireplace) as well as a children's play area in the west, and residential allocations were made in the east. Also during the Second World War, Mount Martha House had extensive use by the military and functioned as a Women's Royal Australian Army Corps (WRAAC) barracks up until 1978.