This is the better of the stone circles at this complex, but it's still not easy to appreciate due to the fact that the stones are very low and embedded in heather-covered peat.
The part of the circle that is most visible is a 4m diameter ring of stones that stand just 30cm proud of the peat. At a few points around the edge there are some stones set raidially. The alignments marked on the plan are almost impossible to spot. There are a few stones sticking out of the peat to the south.
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.