most notably , it was now that the great underground fortress-city of nargothrond emerged , and the wide lands of its dominion ( a central element not only in the legend of turin and nienor but in the history of the elder days of middle-earth ) , with a description of the farmlands of the elves of nargothrond that gives a rare suggestion of the 'arts of peace ' in the ancient world , such glimpses being few and far between .