Rock of Dunamase

"Near to Stradbally stands the Rock of Dunamase, surmounted by a ruined castle that was known to the Ancient Greeks and included Ptolemy in his famous world map of 140 A.D. As befits its age and spooky nature, there's a banshee here too, as well as one of the more terrifying but lesser known Irish ghouls, a hell-hound. The hound is a huge mastiff called bandog, jet black in color with flaming breath. He is there to guard the treasure buried at the heart of the hill and so far he's been successful. Nobody's ever found it."
http://en.wikipedia.org/wiki/Rock_of_Dunamase