158 -- 9 ) that whereas in the lost tales hisilome is declared to be beyond the iron mountains , it is also said ( in the tale of turambar , p. 77 ) that these mountains were so named from angband , the hells of iron , which lay beneath 'their northernmost fastnesses ' , and that therefore there seems to be a contradictory usage of the term 'iron mountains ' within the lost tales -- 'unless it can be supposed that these mountains were conceived as a continuous range , the southerly extension ( the later mountains of shadow ) forming the southern fence of hisilome , while the northern peaks , being above angband , gave the range its name ' .