Although you can see all three of these tombs from quite some distance it is this, the central tomb, that really stands out. This is due not only to its size but also because of the huge illuminated cross that stands upon it.
The cairn appears to be unopened, but some slippage on the southwest side and a large protruding slab could be signs of an entrance there. The cairn stands at least 8m tall and is over 20m in diameter, with no signs of a kerb.
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.