Kill houses, boats, planes, urban complexes... all places we would like to be ready with our gear to play an airsoft game. Places like this US Green Berets are enjoying.
These are military environments, training compounds many times, not accesible to the airsoft community. Difficult but not impossible, as sometimes games have been organized in such orgasmic venues. Event like US OLC.
This is an overview of the game field. Amazing, right?