This is a small stone monument to the place that Geoffrey De Havilland (of Gipsy Moth and Mosquito fame) took his first flight in 1910. It’s on the edge of a field, about 50 metres from the A34. To get there, drive North on the A34 (North of the A303 and of Whitchurch), stay on it past the turning for Litchfield and Dunley, then stop in the first parking layby about 1.5 miles further on. There’s a small sign at the southern end of the layby to the monument. I drove past this hundreds of times before I decided to stop - well worth the few minutes it took!