What is naughty fort and its scope of application?

Naughty Fort of the arbitrariness of its wide range of applications, such as schools, kindergartens, gardens, villas, free zone indoor trampoline park, property district, playground, children's palace, shopping malls, supermarkets, whether indoor or outdoor occasions are able to see its shadow. For a long time, we may misunderstand the naughty fort, that it can only be a child to play, the young people can play like playing the same playground