Birr Castle, the seat of the Earl of Rosse at Parsonstown, is surrounded by a fine park. It is remarkable for its mammoth telescopes, one of which is fifty-two feet long, with a speculum six feet in diameter. Nenagh, at the foot of the Silvermines and Keeper mountains (2,278 feet), is a stirring market town, and possesses a Norman keep in fair preservation. Birdhill brings us to the Shannon, the attractions of which are dealt with in another chapter.