Now Trevor, I had a look through the recent issues of "Land Rover Owner" I have here but I could not get any listings. However, I looked up the magazine "Off Road & 4 Wheel Drive" that's here for years, in fact I'm ashamed to say it's the May 1996 issue
so I don't know if the places listed are still up and running.
Anyway, two places listed that are closest to you are:
Dromoland Off Road Driving Experience
Dromoland Castle, Newmarket-on-Fergus, Co. Clare - (061) 368809. Opened in 1995. Land Rovers for hire aswell.
Rockgrove Off-Road Centre
Coachford, Co. Cork - (021) 334000. Opened in 1994.
Try these out (hope the numbers are still the same) and see how you get on. The one in Cork might not be for Land Rovers though as they mention quads and off-road karts but have a try anyway.
There's more places listed, one in Monaghan and the rest up North, so if you want their details let me know, I have them here.
Off-Roading would be some craic. I'm hoping to get a Defender myself during the summer, have plenty of work lined out for it