Loosely originating in Japan in the 1980s, MilSim events are now bolstered by an active Internet scene. An American presenter, MSATO, claims that MilSim is "fastest-growing extreme sport worldwide." The largest events can attract thousands of attendees, though players must often source their own equipment, such as specific uniforms, radios, and weapons. Attendees are diverse, consisting of hobbyists, military veterans, or enthusiasts as young as 13. In the United Kingdom, airsoft organizers run in conjunction with Live Action Role-Players (LARP) at British Army training facilities, such as Copehill Down and Catterick Garrison. Elsewhere, combat stages are often salvaged from abandoned buildings and private woodland. Many of the larger playfields are leased to ROTC groups or civilian first-responders for their own simulation training.