Built for Owen Wynne in the 1730 on his then 14,500 acre estate by Richard Cassels (who went on to design Leinster House, Powerscourt House and Russborough House) Hazelwood is described as consisting of “a 5-bay by 3-bay main block in three storeys with 2-storey wings on either side connected to the main block by single-storey quadrants.“
Hazelwood House remained within the Wynne family until the 1930s when it was sold to the state. During the next 30 years the mansion went on to serve as both a military barracks and psychiatric hospital. The house was again sold again in the 1960s to an Italian firm, Snia, who built a factory build on the demesne and gardens of the Estate (the factory was later occupied by a Korean videotape firm Sehan Media which also closed down).
The house itself was used by Snia as offices but has been empty and boarded up since 1987. It was sold again in 2006 to a development company whose plan to build houses and apartments on the estate was turned down by Sligo County Council. An order was placed on the property forcing the owners to improve the fabric of the building to ensure its preservation.
The development consortium has since gone into receivership and a Hazelwood Heritage Society has been formed which has called on Hazelwood to be “gifted” to the people of Sligo and developed as a cultural, heritage and educational tourism asset for the region. Today it is in a poor state of repair and very much in state of limbo.