sacrosanct - too important or valuable to be interfered with.

sacrosanct

ˈsakrə(ʊ)saŋ(k)t,ˈseɪkrə(ʊ)saŋ(k)t/

adjective

1. (especially of a principle, place, or routine) regarded as too important or valuable to be interfered with.

   "the individual's right to work has been upheld as sacrosanct"

   synonyms:

   sacred, hallowed, respected, inviolable, inviolate, unimpeachable, unchallengeable,invulnerable, untouchable, inalienable, set apart, protected, defended, secure, safe,unthreatened "the rights of parents are sacrosanct for this government"