Scots Pines
These waymarkers were used by drovers to guide them to a favourite inn, or a safe river-crossing, in dead ground. Picture #1 is of a clump of pines above the Wye crossing at Erwood, South Wales.
Pines are fast-growing, evergreen and stand out like an alien species – they appear almost black from a distance. According to John Trimmer, drovers from North Wales brought pine-cones down with them and planted them in clumps of three or five near the inns they wanted to recommend. (In fact in the 1600's it was drovers who re-introduced pines to the south where they had died out after the last Warm Period.)
Picture #2 is taken in Featherbed Lane leading to Coldharbour Barn. Honest!
Of course we are often seeing the descendants of the originals.
(Warning: the railway companies used the same system to mark their stations in the age when people walked to them.)
Pine Trees above Erwood
Pines near Mixbury