It was quite a walk over the mountain to reach this cairn, but it is a pleasant walk and the cairn is in a great location, so it's worthwhile. The cairn occupies a spot on the end of a small promontory/ledge on a north-facing slope overlooking a deep, wide valley.
The cairn has been robbed away so that the chamber within has been left exposed. There is a piece of roofslab lying around and the chamber is half-filled with soil. The cairn is about 10m in diameter and about 1.5m high, but it's hill-edge position makes it look much taller from all angles bar from the west.
There are traces of a kerb and the chamber is elongated, so there is a fair possibility that this is actually a passage tomb.
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.