WordNet sense 1 (not capable of being obtained):

unobtainable, untouchable, unprocurable

WordNet sense 2 (not available or accessible or at hand):

unavailable

WordNet sense 3 (inaccessibly located or situated):

unapproachable

WordNet sense 4 (inaccessible and sparsely populated):

remote

WordNet sense 5 (capable of being reached only with great difficulty or not at all):

unaccessible