I've driven up the lane and tried to spot these stones a couple of times, but with no luck. I'd given up today as well when I the farmer approached up the track. A quick Good Morning and a chat, and I soon found out that the reason why I couldn't see the stones was that the track I was driving on wasn't the track on the map. The stones are to the east of the new track, not the west, so I'd been looking in the wrong place. I was also standing just 20m from the stones whilst talking to him.
The stones are incorporated into a dry-stone ditch below some tall pine trees. This, and the fact that they're often covered in ivy, makes them quite hard to see. I found the stones and stripped some of the ivy off them. As I was standing on the top of the field wall when I did this I was disappointed by the larger stone's size. Then I jumped down and flattened the nettles and weeds at the base of the wall revealing the full 3m of the tallest stone. It's a whopper! Such a shame it's hidden from view. The smaller stone is to the west of the other and is a little under 2m tall.
The trees and bushes around these stones make it difficult to assess any possibilities about why they were erected here. It isn't possible to walk away from the stone to get a clear view, because the farm is now a deer farm and all the fields are surrounded by 4m high fencing. Luckily for us the stones were left out of the enclosures, so we can go and see them ... if we can find them.
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.