Geograph - photograph every grid square

The bench mark is on the milestone beside the A683 that probably dates from the early 19th century. Set on Sedbergh to Greta Bridge turnpike road, 1762. (S = Sedbergh; KL = Kirkby Lonsdale). For a view of the milestone SD6290 : Milestone near Killington and Link
A bench mark is an Ordnance Survey arrowhead sign found on walls, bridges, churches and specially erected triangulation pillars where the altitude above sea-level has been accurately measured by surveyors. The arrowhead points to a horizontal line above it which marks the exact altitude.
With rivets and pivots there is no datum (horizontal line) cut, the pointed-to horizontal surface defining the datum height.