In 1786 Wilson refers to Coolquill as the seat of Mr. Gahan. The property is labelled "Coolquill Castle" on the 1st edition Ordnance Survey map and indicates that it was built on to a tower house. Coolquill was held in fee by Colonel Palliser in the mid 19th century. He was married to Anne Glenstanes. The castle was valued at £5. The castle ruin and other buildings are still extant at the site.