The castle stands on the verge of a precipitous rock on the south-east corner of the town.  Its walls are triangular in shape, being said to resemble a Welsh harp; they are fifteen feet thick, and are strengthened by twenty-one towers.  The most striking portion is Queen Eleanor's Tower; the most curious is the Fragment Tower.  Two centuries ago some of the inhabitants, searching for slate, undermined it, when a portion fell, leaving a perfect arch, since which period not a stone has fallen away, and it is still as firm as ever.  We wandered round and round the castle, wondering at the massiveness of the masonry.  It would have still been perfect--for it was spared by the Parliamentary forces who captured it--had not a Lord Conway, in Charles the Second's reign, stripped off the timber, lead, and other materials to sell.  The vessels, however, conveying the materials to Ireland, were lost, and the greedy baron gained nothing by the barbarous proceeding.