This is after Sean had been denied the hand of Mary Kate by her brother Red Will Danagher, Sean takes to riding his black hunter, as Father Peter Lonergan says, " hah those were the bad days with Sean a face as dark as the black hunter he rode it wouldn't be long before one or the other broke it's neck". This tower was seen in the background when Sean was riding his black hunter it's called Joyce's Tower built in 1864 and is one hundred foot tall and is situated in the grounds of Ashford Castle. But you can no longer see this tower from the road where Sean rode his horse because of the density of the trees, you can just make out the tower in the middle of the photo.