unenclosed
/ˌənɛnˈkloʊsd, ˌʌnɛnˈklɔʊzd/Definitions
1. adjective
not enclosed or surrounded by walls or a covering
“The garden was an unenclosed space where children could play freely.”
2. noun
an area of land that is not enclosed
“The unenclosed area of the farm was used for grazing animals.”