Bench-marks in the Dales - heritage worth protecting

It was in the early years of the 19th century that the Ordnance Survey (OS) commenced its mapping work in the Dales. The initial surveys formed part of the Principal Triangulation of Great Britain and laid the foundations for the maps that we have today. Later surveys complemented the earlier ones, providing increased coverage of the country and greater detail. This had become necessary because of rapid urban and industrial growth, expansion of the transport network, and changes to patterns of agricultural land holdings.
The work that was undertaken left its own very distinctive marks in the landscape and many of these survive today, although they are little known to the majority of people. Some survey marks are small and inconspicuous, others are more prominent. Together they are remnants of a survey methodology that is no longer in use; map-making is now based on digital data acquired via satellites and GPS ground receivers. Most of the marks created by the OS are essentially redundant; nevertheless they are significant historical artefacts that are worthy of protection because of the part they played in mapping the nation.