sacrosanct(beyond alteration, criticism, or interference, especially due to religious sanction; inviolable) adjective [UK: ˈsæ.krəʊ.sæŋkt] [US: ˈsækro.ʊ.sæŋkt]
unassailable(undeniable, incontestable or incontrovertible) adjective [UK: ˌʌ.nə.ˈseɪ.ləb.l̩] [US: ˌʌ.nə.ˈseɪ.ləb.l̩]