This really took some finding and we'd almost given up on it when I saw it. Carved into the upper surface of this 1.4m (L) x 1m (W) x 1m (H) rock are 6 large cups (almost of bullaun size), one small cup and one much enlarged solution pit that is around 20cm deep.
Two lines are cut across the surface between several of the larger cups and diverge around the smaller one.
The siting of this stone so close to the lough does give me the impression of an early form of bullain stone.
This is an explanation of (and a bit of a disclaimer for) the coordinates I provide.
Where a GPS figure is given this is the master for all other coordinates. According to my Garmin these are quite accurate.
Where there is no GPS figure the 6 figure grid reference is master for the others. This may not be very accurate as it could have come from the OS maps and could have been read by eye. Consequently, all other cordinates are going to have inaccuracies.
The calculation of Longitude and Latitude uses an algorithm that is not 100% accurate. The long/lat figures are used as a basis for calculating the UTM & ITM coordinates. Consequently, UTM & ITM coordinates are slightly out.
UTM is a global coordinate system - Universal Transverse Mercator - that is at the core of the GPS system.
ITM is the new coordinate system - Irish Transverse Mercator - that is more accurate and more GPS friendly than the Irish Grid Reference system. This will be used on the next generation of Irish OS maps.