This is well worth checking out, if only because there are many different sites of archaeological interest in close proximity.
I came here with the bullaun in mind, having seen it on archaeology.ie. It's about a metre and a half long by half a metre wide and has one shallow basin. It's now cemented into the side of a shrine to St. Brigid which in turn sits beside a dry holy well.
I had a delightful companion during my time here – a gorgeous little puppy that followed me down from the house where I attempted to ask for permission to visit the well.