The 19th @-@ century antiquarian Angharad Llwyd mentioned the church in her history of Anglesey . She said that the architecture was of " the rudest kind , [ which ] bears testimony to its great antiquity . " She recounted that a fox had once taken shelter in the ruins , and when it was dug out , the vault was discovered , " containing several human skeletons , which crumbled into dust , when exposed to the air " . She added that further exploration of the vault then revealed " a large mass of human bones , several feet in depth " .