Mains(ruins) Appears to be some sort of homestead farm, or at least the ruins of one, situated above the track that runs behind the Hill house.
Listed on a map series, OS Six inch, 1843-1882. on the Nation Library of Scotland website https://maps.nls.uk/geo/explore/#zoom=15.7&lat=56.02344&lon=-4.73872&layers=5&b=1
