 The castle fell into disrepair in the late 17th century, was leased out, and was not restored until around 1779, when parts of the demesne were landscaped and some of the estate features were added.Significant reworking was carried out from 1803 to 1813 under the supervision of Francis Johnston, and in 1841, much of the castle was demolished and rebuilt (using much existing material) by The 9th Earl of Fingall, in the style of a small Windsor Castle.The two towers added have the dates 1181 and 1841 inscribed, and at the time of completion, it was said that Killeen had 365 windows.