I've been thinking about this for a while, and I have absolutely no idea what the largest forest in Ireland is. Google hasn't given me any answers either. I can imagine that the size of forests has been altered greatly over the last few years due to new plantations and the harvesting of older forests, but I'm sure someone must know.
i would say the farming and forestry forum would have your answer.
i would say around the magillacuddy reeks in kerry.
I'm not sure about this but I'd guess the mountainous areas are where you would find the most extensive forest cover.
I think the Slieve Aughty Mountains in Galway/Clare might have the most extensive area of continous forest cover.
Wicklow mountians also have significant areas of forest.
Moved from AH
The largest that I have ever come accross is one in the Silvermines in Tipp, it is over 250 Ha/550 acres. It is owned by one of the private pension funds.
Most forests planted in the last 10 years are not bigger than 50Ha as they would need an Environmental Impact Assessment which is considered prohibitively expensive.
In all fairness- if you go up towards the Northwest- there are several privately held forests- often on poor cutaway bog, often backing onto one another- that in some cases can be literally thosands of acres in size. BOGFOR have some very good aerial/satellite photography (including the Landsat series from the early 1990s) showing exactly where forestry is- along with all other land uses. There is a key to identify what the different colour grades. I'm not suggesting purchasing the maps- unless you've recently won the Euromillions however.......