Ferns Castle was built around 1220, but parliamentarians destroyed the castle and executed most of the local population during Cromwell's rampage through Ireland in 1649. The ruins are thought to stand on the site of Dermot MacMurrough's old fortress. A couple of walls and part of the moat survive incongruously in the middle of town; you can climb to the top of the one complete tower. The visitors' centre holds regular exhibitions relating to the history of the town.
