Castle Hotel in Co. Monaghan is nestled on 1,000 acres of undulating Irish countryside, dotted with ancient woodland and glittering lakes, Castle Leslie Estate Monaghan is one of the last great Irish Castle estates still in the hands of its founding family. Since the 1660s, the distinguished and somewhat individual Leslie family have lived on the Castle Estate, welcoming everyone from politicians to poets, ambassadors to ufologists; all the time making their home into one of the finest luxury hotels Ireland has to offer.