no-go area
noun [ C ] informal uk/ˌnəʊˈɡəʊ ˌeə.ri.ə/ us/ˌnoʊˈɡoʊ ˌer.i.ə/
（尤指城镇里武装分子控制的）危险地带，禁区
an area, especially in a town, where it is very dangerous to go, usually because a group of people who have weapons prevent the police, army, and other people from entering