Use Wiki to work out the co-ordinates of the cache.
The Ridge of Capard is the 'A' highest point in the Slieve Bloom Mountains. The Ridge of Capard's summit is at an altitude of 'B' metres.
The cache is at the following coordinates
N53 A.493 W7 27.(B+26)
It is possible to drive to within a metre of the cache but do take a walk onto the boardwalk if you've come this far!
You can check your answers for this puzzle on GeoChecker.com.