Inflatable structures are large col-air structures that people (usually children) can bounce on for recreation. They have been marketed such names as Moon Bounce, Astrojump, Moonwalk, Bounce house, SpaceWalk, in the US, bouncy castle or inflatable castle in the UK and parts of Australia, and as jumping castles in Australia, New Zealand, Canada and South Africa. They are often in the shape of a castle. The walls and floor are soft.