Reek Sunday is an annual pilgrimage that takes place on the last Sunday of July in Ireland. It is centered around Croagh Patrick, a mountain located in County Mayo, which is considered a sacred site. Pilgrims climb the mountain to honor Saint Patrick, the patron saint of Ireland, who is said to have fasted there for 40 days in the 5th century. During the event, thousands of people ascend the 764-meter peak, often barefoot, as a sign of devotion. The climb is both a spiritual journey and a physical challenge, attracting participants from various backgrounds, including locals and tourists.