As I approached this large 3m long, 1.5m wide flatish rock I didn't hold out much hope. When I first looked at it closely I thought I could see a couple of cup marks and that was it.
Then I tried to see if I could highlight the very shallow and faint markings by rubbing some grass across the face and was amazed at what was revealed.
The marking can be split into two panels. On the one side there is a cup mark with double ring and gutter - the outer ring is 30cm across.
The other 'panel' is astonishingly beautiful. More and more of this was revealed as I moved across the surface in stunned silence. There are around 12 parallel lines, 30cm in length, going across the stone. Next to these is the real show piece - this consists of a long groove at right angles to the group of lines along the sides of which are 5 cup and rings which connect into the groove.
This is the nicest example I have yet seen.
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.