This cross stands on a horrible modern concrete stand at the south end of Main Street in Blackrock, Dublin. The cross head itself is quite wonderful with a relief face carved on it.
The stone is said to be much older than its christianised form suggests. It used to be a boundary marker for the City of Dublin that now stretches 4km further south.
It is believed that the face is that of an earlier pagan god.
From Dublin head south along the N11 and then take the N31 towards the coast. Turn left into Blackrock and park somewhere near Main Street. The cross it at the southern end opposite an establishment called The Mad Hatter.
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.