Photographed by Dave Brewer in Dartmoor Boundary Markers, this is at present (2023) a most overgrown boundary stone that is set on top of the wall at Ducksmoor, to the north of the B3212.
To help you find the stone, head to where the ‘for sale’ sign is (we can’t guarantee that will be there next time!) and look on the wall (ideally outside of the summer months).