Knock is a village in County Mayo, Ireland. Its notability is derived from the Knock Shrine, at which the Virgin Mary, together with Saint Joseph and John the Evangelist, appeared on 21 August 1879. In the 20th century Knock became one of Europe's major Catholic Marian shrines, alongside Lourdes and Fatima. One and a half million pilgrims visit Knock Shrine annually. Pope John Paul II, a supporter of devotion to the Virgin Mary, visited Knock in 1979 to commemorate the centenary of the apparition.