Monellan Castle was a large castellated mansion

Mansion

A mansion is a very large dwelling house. U.S. real estate brokers define a mansion as a dwelling of over . A traditional European mansion was defined as a house which contained a ballroom and tens of bedrooms...

, in Killygordon

Killygordon

Killygordon , is a small village in the Finn Valley of east County Donegal, Ireland. It has a population of 114 and is located on the N15 between Ballybofey and Castlefin. The separate townland of the Crossroads lies half a mile from Killygordon, however, they are often regarded as one...

, Co. Donegal, Ireland. It was constructed for the during the 18th century for the De Lap (also spelt Delap) family, a British military family who acquired the estate in return for services rendered to the crown. the family also owned estates in Buckinghamshire

Buckinghamshire

Buckinghamshire is a ceremonial and non-metropolitan home county in South East England. The county town is Aylesbury, the largest town in the ceremonial county is Milton Keynes and largest town in the non-metropolitan county is High Wycombe....

, England.

During the 1930s, the castle and its estate was acquired by the Irish Land Commission

Irish Land Commission

The Irish Land Commission was created in 1881 as a rent fixing commission by the Land Law Act 1881, also known as the second Irish Land Act...

which redistributed to the land to local tenant farmers, as was the policy at the time. The castle was then, with support from the Irish Government, demolished.