Pilgrims progress on island of self-denial

Station Island, Lough Derg, Co Donegal, a pilgrimage site since St Patrick visited in 445AD. Very important in medieval times, the lake is the only Irish site on a world map of the 1490s.
I am going to arise soon, as Yeats advised long ago, and go to the real Innishfree, which is Lough Derg in the County Donegal, otherwise known as Saint Patrick’s Purgatory, and I will suffer sore there for three days, barefoot and starved and eaten alive by swarms of bull midges that never go away, and I will report back to ye a week later, if I survive yet again, because I have been there before several times, especially as a schoolboy, and that is not alone the pure truth but also a solemn promise which I have to honour before the 1,000-year-old pilgrimage season on Station Island in Lough Derg outside the village of Pettigo, ends at the end of August.