A note on the Irish 1:50,000 maps.

Although the Irish Grid covers the whole island,
maps for Northern Ireland, issued from Belfast, imitate those of Great Britain, while those for the Irish Republic retain the tradition of coloured contours and elegance.
The Dublin Ordnance Survey's Discovery series marks almost every stone monument, so that nearly every megalith listed on this site is marked with a red dot, and labelled "Megalithic tomb" or "Standing stone". They are thus invaluable to the megalith-hunter.
However, those areas of Northern Ireland covered by the Southern Discovery series have no monuments marked:
they stop at the Border!

Northern Ireland's Discoverer maps do not mark all megaliths, though they do mark some megaliths in areas of the Republic which they cover. Tombs tend to be anachronistically labelled Chambered Grave in Gothic script - though the script has changed in the newest maps.

A few of the map references given on this site may be slightly inaccurate.

I should be grateful for any corrections to grid co-ordinates or any other matters of fact.

Instructions on how to use grid references are printed on every map.