Blayney Castle, renamed Hope Castle in the early 1850s, stands in a demesne or park on the eastern edge of Castleblayney town itself. It is thought that this demesne pre-dates the current 'castle'; that large parts of it had already been laid out by the early 1770s. The demesne was substantially improved for the 11th Lord Blayney by William Sawrey Gilpin in the early 1830s. However, the demesne has deteriorated since it came into public ownership in the 1980s. Almost all of the large Italianate Victorian extension to Hope Castle was demolished by Monaghan County Council in the 1980s.