25 years after Mick Fowler, Nikki Duggan and Steve Sustad summited in 1990, Irish sea stack fanatic Iain Miller has made the second ascent of the 45m high Dùn Briste - or 'broken fort' - sea stack, 50 metres off the north Mayo coast at Downpatrick Head, Ireland, with partner Paulina Kaniszewska. Although intending to repeat the original route Doonbristy MXS, Iain discovered a new line which he has christened Chaos Theory XS.
It would be interesting to know more about the building remains on the top. By who, why and when they could have been built. And how the people got on top in ancient times... (are there traces of ladders? Fishermen where used to climb scary cliffs, but to build something I guess they had installed something more safe...)
Sorry for the ignorance, but I know nothing about seastacks
'The stack has a remarkable history, having separated from the mainland relatively recently in 1393 following a major storm. People left stranded on top of the stack were reportedly rescued by a ship's ropes and the remains of buildings in which people were living on the night of the storm are still visible today on the flat summit of the stack.'
People were living in the houses on the mainland before it separated, so they ended up stranded on the stack.
It would have been a headland originally when people would have settled on it, then holes would have developed through the peninsular. Storms would have kept enlarging these arches until they finally collapsed leaving the sea stack as we see it today. Pretty well the same process for all sea stacks.