It was still inhabited in 1684, when it was described by Reverend Symson in his Large Description of Galloway as "a good strong house", but by 1838, when it was painted by George Colomb, it had been abandoned and had fallen into a ruinous condition.

There were iron grilles in the windows, and it was further protected by a high wall, but its defensive arrangements were weakened by the fact that one of its ground floor chambers does not communicate with the other rooms of the tower, and was only accessible from the outside.

Archaeological evidence for a walled courtyard, gardens and ancillary buildings survives beneath ground level in the surrounding field.

Plunton Castle's romantic setting inspired Walter Scott's poorly received melodramatic play, The Doom of Devorgoil.

Plunton Castle is situated in farmland, about three miles south-east of Gatehouse of Fleet, and is approached by a farm track from a minor road.

This was furnished with a plain fireplace, about 1.8 metres (5.9 ft) in width, beneath a corbelled-out lintel, built into the middle of the west wall, with an aumbry to its left.

[5][6] The room was lit with windows in all four walls; these have had much of their dressed stone removed, but what remains shows signs that there were originally iron grilles in each of them, with opening shutters beneath fixed glazed panes.

[5][6] Fireplaces in each of the gable walls of the second storey suggest that it was divided into two chambers, also lit with windows, but the wooden floor is no longer present.

[5][6] The attic above these, also divided into two chambers with gable fireplaces, gave access to the turrets, which are supported with corbels and a top row of dentils, at the north-west, north-east and south-east corners.