It is about the size you see on your screen. No local names that I can see throw any light on it. Weird though isn't it? It is thought that a pagan building was on the hilltop which then became a small Saxon church before the present Norman foundations were laid. Little signs of erosion so I'm guessing that it is recent or has been under cover for a long time. Folklore says the Devil left the print when he tried to kick the church down - so that's no great help.

Love your photographs - they really are stunning.