During World War II, the mountain was used as a military base by the RAAF and the US Navy. It was converted to a vast explosives depot and at one stage held more than 120,000 tonnes of explosive weapons. When darkness fell the lookout bristled with search lights in an amazing display as soldiers kept an eye out for enemy planes.anti-aircraft guns and searchlights were located on the lookout. Mount Coot-tha was also the site of US Naval Ammunition Depot (Navy 134) supplying submarines at the Capricorn Wharf at New Farm (Teneriffe) in Brisbane.