Glanusk Park is an estate in Wales, United Kingdom. It is situated near Crickhowell, Powys. It was established in 1826 by a 'retired' ironmaster, Sir Joseph Bailey. The park features in the hereditary title Baron Glanusk which was given to Sir Joseph's grandson, Sir Joseph Russell Bailey in 1899. At that time Baron Glanusk was the Lord Lieutenant of Brecknockshire. Glanusk Park and Estate is privately owned by the Legge-Bourke family. It is situated in the countryside of the Usk Valley, South Wales in the Brecon Beacons National Park, and is one of the largest privately owned Estates in Wales.