There was once a very strong man living on the top of Knock-fierna. This man was one day walking along the fields when he came across a big stone he wanted to show his friends who were with him how strong he was. First he moved the muscles of his hands couple of times, then he got the stone and threw it down the big hill and it landed in the middle of a big field in Rathkeale and from that day out it was called rock field.