Reports of visions of purgatory and paradise persisted for many centuries serving to attract

Reports of visions of purgatory and paradise persisted for many centuries, serving to attract pilgrims from the continent. The island was famed internationally, and was the sole Irish landmark on several maps of the Renaissance period. He received visions, they say, depicting "not only the torments of the wicked but also the joys of the blessed".In ancient times, many were ready to believe that this faraway place could provide access to the afterlife, since Ireland was regarded as one of the "final parts of the world". But, even earlier, Celtic pagan cults were strong in the area, so that its tradition could be an example of the familiar process by which Irish Christians have deftly absorbed elements of previous belief systems into their own.Tradition has it that St Patrick came to the lough around 700AD, spending time in a cave, where he is said to have seen visions of purgatory. Since at least the sixth century it has been known as a monastic retreat and a place of prayer and contemplation, an Irish version of the biblical desert. The vigil is a trial for the strongest of bodies and the stoutest of hearts."The lough itself has an understated, brooding beauty and a sense of remoteness.

According to Father Joseph McGuinness: "All pilgrims have to contend with the twin demons of exhaustion and discouragement. "Tony Blair could be here and he wouldn't get any favours."Several pilgrims admitted that the sleepless night, spent in the island's basilica, was a particularly testing ordeal. A centuries-old Catholic text prescribes "keeping vigil and praying without respite, without leave to sleep - as though one were at the very gates of hell". "But afterwards you think it's 100 per cent worth it, definitely." A teacher from Monaghan agreed: "There were times during the night when I said, 'I just want to go home, there's no way I'm going to last, why am I here?' But then you get over that and you're grand again."This effect is exactly what the Lough Derg authorities are aiming for. Today's pilgrims testify to the effectiveness of the practice. "It's tough at two o'clock in the morning, when you get a freezing breeze down your neck and you can't sleep and you're hungry," said Nuala McParland, a Donegal doctor.

"People tell you amazing things about their lives," said one. "Things that they wouldn't tell a stranger anywhere else."A number commented on the sense of bonding that came from the discarding of footwear "Everybody's treated the same," said Ciaran Rouse from Mayo. They are required to stay continuously awake for 24 hours, from the evening of their first day.There are periods of silence and contemplation, and other times when pilgrims chat together. No children are allowed, and pilgrims must be fit.The pilgrimage exercises consist of a sequence called a station, a well-known Celtic form of devotion involving mantra-style prayers said while walking barefoot around outdoor "beds" devoted to saints.But for much of the time there are no beds for the pilgrims themselves, since a central part of the experience is a period of sleep deprivation. She has just received an MBA for a research project in which she chronicled where visitors came from, and what drew them to Lough Derg.She recorded an increase in the number of male visitors, including young professionals in their mid-twenties. "There's more stress on the males and they're looking for something," she reported.