The annual pilgrimage climb up Croagh Patrick in Co Mayo will this year be dedicated to people who have made Ireland their new home.
The tradition of climbing the 2,015 feet-high holy mountain on the last Sunday in July stretches back to 441AD when St Patrick reputedly fasted on the summit for 40 days and 40 nights.
It was confirmed the Archbishop of Armagh and Primate of All Ireland, Dr Sean Brady, will lead this year's pilgrimage. It is the first time that an Archbishop of Armagh has climbed the Holy Mountain since St Patrick.
The Archbishop of Tuam, Dr Michael Neary, said he was dedicating the theme of this year's pilgrimage to those people that have made Ireland their new home.
The pilgrimage climb on Reek Sunday will begin in the village of Murrisk, and Mass will be celebrated at the summit at 10.30am.
The climb has reputedly been carried out uninterrupted for over 1,500 years, with around 30,000 people climbing the mountain on the day and 100,000 throughout the year.
Meanwhile, Peter Jordan of Mayo Mountain Rescue advised climbers to be prepared for the 7k round trip up the 764m mountain.
Mr Jordan said people should wear proper footwear and ankle protection.
Speaking on radio this morning he said that he didn't recommend climbing the mountain barefoot but if people did they should bring a spare pair of shoes in case they get tired.
He also advised people to dress with plenty of layers and to bring a minimum of a bottle of water.