Our Lady of Bethlehem Abbey, a Cistercian monastery in Portglenone, County Antrim, Northern Ireland, was founded in 1948 by Mount Melleray Abbey in County Waterford. The monks bought Portglenone House, a country mansion built about the year 1810 by the Church of Ireland Bishop, Dr. Alexander who demolished the local castle . History records that Sir Roger Casement often stayed in the house in the early years of the 20th century.