knock ("an cnoc" in irish, meaning "the hill" – but now more generally known in irish as "cnoc mhuire", "hill of (the virgin) mary") is a small town in east county mayo in ireland. knock's notability comes from the knock shrine apparition of 1879. at 8:00pm on 21 august 1879, it was reported that the virgin mary, together with st joseph and st john the evangelist, appeared to local people.