Visited this place about 6 years ago on a hitch-hiking tour of Cork and Kerry. Having been dropped off in the town of Cahersiveen during a funeral we booked into the local hostel and then walked over the bridge to the north of the town. Heading west we came across this fort, at the time I was not what you would call well up on things ancient but remember being overwhelmed by the size of the place. The walls towered above us and all seemed so clean, no greenery growing out of the gaps etc. Kathy, my partner, climbed up the inner steps to the top of the wall and then had a "moment" when she realised she had to then go down!
Looking back at the OS map I realise how much we missed in the area, must make a note to go back....with our own transport.
Nearby to the fort is a wonderful old medieval castle, half of it has fallen down giving it the look of one of those cross section drawings you see in books.