In the year 1215 the lands of Drymenagh and Tyrenure was granted to a Norman knight, Hugo de Bernivale, who had come over with Strongbow, these lands being made over to him by a royal grant of King John. De Bernivale selected a site beside the “Crooked Glen”, the original Cruimghlinn, that gives its name to the townland of Crumlin, and there he built his castle. This “Crooked Glen” is better known today as Landsdowne Valley, through which the river Camac makes its way to the sea. The little river Camac, was within living memory a fine trout river, and has been classified by DCC as found to support a broad range of biodiversity which includes fish, invertebrates and plant life (willows and water cress) in the river Camac. Woodland on a bank of the river Camac in Lansdowne Valley Park was also found to contain many indigenous and rare species.