However the same author had stated previously that the Earl's father, Thomas Fortescue, had purchased an estate near Dromiskin in Ireland, named Randalstown, which he renamed Clermont Park. Clermont Park is an estate within County Louth and is near to Lurgangreen, Mooretown and Blackrock and Dromiskin. The mansion house was burned down by armed men in February 1923 when owned by Col. Charles Davis Guinness, county representative of the Irish Unionist Alliance, in one of the many politically motivated arson attacks at that period. An Industrial estate known as Clermont Business Park now occupies the site. Only the gatehouse survives, next to St Paul's Church, Haynestown. A Neolithic chambered cairn dating from about 4000-3500 BC, survives atop Black Mountain in the Cooley Mountains in County Louth, in which was situated Fortescue's estate, known in native Irish as Carnán Mhaighréid Náir, also known as Black Mountain Chambered Cairn and Clermont Cairn.