A border castle which was the birthplace of a leading 19th century unionist and MP has fallen into disrepair and urgently needs preservation work, the National Trust for Ireland has warned.
Castle Saunderson on the Cavan/Fermanagh border has been included on An Taisce's list of the Republic's top 10 most-at-risk buildings.
The list - released for the first time - also includes Carstown House, a rare example of a 17th century Irish manor house near Termonfeckin in Co Louth, and Iveagh Market, an indoor market in Dublin's Liberties area.
Castle Saunderson was the family home of Colonel Edward Saunderson, a leading anti-Home Ruler.
Born in the castle in 1837, he first entered Parliament as an MP for Cavan in 1865 as a Liberal before becoming a Conservative four years later.
He lost his seat in 1874 but became an MP for North Armagh a decade later.
A prominent Orangeman, he was known for his staunch opposition to Home Rule.
He was one of the signatories of the manifesto of the Ulster Defence Union (UDU) - a group launched to oppose the 1893 Second Home Rule Bill.
The UDU later became the Ulster Unionist Council, which was a precursor of the Ulster Unionist Party.
Following Col Saunderson's death in 1906, a bronze statue of him was placed outside St Mark's Church in the centre of Portadown, Co Armagh.
The Saundersons owned the 300-acre estate and castle until it was sold to a London-based businessman in 1977.
The estate was sold again in the early 1990s.
The main buildings are now the property of Coillte Teoranta, a forestry company owned by the Irish state. An Taisce said Coillte has no plans to develop the buildings.
The castle, built around 1835, incorporates the fabric of an earlier house built around 1780.
Ian Lumley from An Taisce said it was concerned by the castle's state of disrepair.
"The main building which forms the focal point of Castle Saunderson has suffered signs of deterioration for some years," he said.
"The Church of Ireland church in the grounds has been refurbished as part of a project by Scouting Ireland but the main building is owned by Coillte."
Mr Lumley said the castle should be preserved due to its architectural significance.
"Like quite a number of Irish country houses it would have been built in a plain 18th century style," he said.
"Then with the 19th century it was altered in a Tudor Gothic style. Crom Castle in Co Fermanagh would be similar."
He said An Taisce was hoping that remedial work could be carried out to preserve the house from further deterioration.
"These houses are important assets and if we lose them we lose part of our history and heritage," he said.
"If they are not maintained then it makes the possibility of refurbishment that much more difficult."
