This is a very impressive hill but i couldn't really see any sign of the hill-fort on it but I think it may be worth a look another day. It looks like a very easily defended site so would be perfect for one. There also seems to be quite a few standing stones around the foot of it with the hill as there focus.
Edit 15th May 2007
Knockroe is a very impressive hill-fort. It has a bank about 1m high and about half of it and the rest is protected by shear cliff. The whole hill seems to be full of monuments and old field walls however I'm not sure what period they are from although the mound and the barrow stick out to me as being prehistoric/ iron age.
There is evidence of a well between the two peaks of Knockroe and this would have been of massive importance to a defensive site.
It is also intervisible with the col on Knockfennel to the south-west.
I was surprised to see this monument and at first I thought this was the hill-fort marked on the map.
However it appears to be some kind of three banked mound. Perhaps a ring-fort or a barrow.
It reminds me of the Tlachtga on the Hill of Ward in Meath.
So perhaps it may have had some kind of ceremonial function?