 Boyle also had a substantial residence at Youghal, besides Myrtle Grove, known today as "The College", close to the Collegiate Church of St Mary Youghal.Order on the Boyle estates was maintained in 13 castles which were garrisoned by retainers.The town of Clonakilty was formally founded in 1613 by him when he received a charter from King James I of England.