Originally a home of the MacAdam branch of the Barry family, sold to the Lawless brothers in the 1770s and soon afterwards bought by William Tonson. In 1786 Wilson refers to the seat of Lord Riversdale, close to Rathcormack. The house was occupied by the Reverend John Bolster in the early 1850s and valued at £39.15 shillings. Slater refers to it as the seat of W.A.S. Riversdale in 1894. William Alcock-Stawell succeeded to this property in 1861 and took the additional name of Riversdale. Lisnagar was sold in the early 20th century. This house is still a residence.