An unearthly rock formation in the shape of an erect penis complete with testicles in the Mahon Valley in the Comeragh Mountain range, pronounced man valley, which is an unfortunate enough coincidence. Legend has it that if you spit on Dicky Rock you will receive the gift of the shag!
'A thing of' is a very Irish way of describing an inanimate object, usually a container or packaging of sorts. Be it down to laziness, or actually not knowing the name of what the object is, this expression has many uses.