|Magheracar - Wedge Tomb|
First thing I will say is that this is a very poor example of an undeifferentiated passage grave. The second thing I will say is it is in the most incredible location. The north of the cairn has actually fallen into the sea and the rear orthostats are actually within 30cm of the cliff edge. I really don't know how long it can hold on.
This site is (once more) ruined by the proximity of modern dwellings and urban sprawl. With no houses around this would be a wild, wild place indeed. See it while you can.
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.