The Bunnet Stane (or bonnet stone) is a rock formation near the hamlet of Gateside in Fife, at the foot of West Lomond.
This person was an elderly lady who, as a child, spent holiday time at the nearby farm of Wester Nether Urquhart.
In her letter, she described an old man (possibly an ex-soldier) who was given permission by the farmer to make himself a small bothy which he occupied while employed as a shepherd.
The walls bear grooves, notches and small platforms which are likely to have served the purpose of partitioning off, say, a sleeping area or storage.
Both the Bunnet Stane and the car park are marked on the 1:25 000 OS Explorer map (No.370 - Glenrothes North, Falkland & Lomond Hills).