Ash Island is a former Royal Australian Air Force (RAAF) radar station that was active in the Second World War. It had the designation 'RS131' and was protected by fighters from RAAF base Williamtown. Other radar stations were located around Australia and also in New Guinea and the South West Pacific area. However, the existence of RS131 was a well guarded secret during and after the war. On site is a stainless steel plaque that was unveiled during a ceremony in 1995, to acknowledge the 50th anniversary since the end of the war. It is mounted on a concrete igloo that was the operations building during the war. Remembrance Day commemorative services have been held on the island. Note: Ash Island is part of the Hunter Wetlands National Park, which is managed by the National Parks and Wildlife Service (NPWS). NPWS has prepared a conservation management plan for the 131 Radar Igloo buildings. The address and location of the radar site given on this listing is an approximation only. Signage is located on the island to assist visitors.