2000 The Operational Base for the Stithians/Perranwell Auxiliary Unit was built at a disused quarry at Pelean Cross. It was sited about 400 yards NE of Ponsanooth village and three quarters of a mile SW of Perranwell village, half way between the Sparnick railway tunnel and the Ponsanooth railway viaduct. The underground bunker was a few yards to the W of the railway line.
It consisted of two rooms, with an entrance and emergency exit, and was constructed of timber and corrugated iron sheeting. Nothing remains at the site today. The small copse which hid the quarry during the war has virtually disappeared owing to elm disease.