Listowel Castle was built in the 15th century and was the last fortress of the Geraldines to be subdued. It fell after 28 days siege to Sir Charles Wilmot on the 5th November, 1600, who had the castle's garrison executed in the following days. Today, the remnants of the castle include two of its four towers, which are joined by a heavy curtain wall, and the unusual feature of an arch below the battlements.