no-go

a no-go area an area which is dangerous or impossible to enter or to which entry is restricted or forbidden.

☞ As a noun, no-go was first used in the late 19th century in the sense of 'an impracticable situation'. Its use in this phrase, with the sense of 'no entry', is particularly associated with Northern Ireland in the 1970s.

1971Guardian For journalists and others, the Bogside and Creggan estates are 'no-go areas', with the IRA in total effective control.