The McDermott’s official residence was on The Rock, now called Castle Island. On this site, Lord Lorton built a folly castle as one of the adornments to Rockingham Demesne.
In 1832, Weld describes as part of “the castle proper” 2 rooms, one above the other, each 36 feet by 22 feet, with walls of 7.5 feet thickness. Whether this refers to part of the original castle, or the later construction is unclear.
This folly castle, used as a summerhouse, was gutted by fire shortly before the Second World War.