The Ordnance Survey bench marks are not showing on the maps?
Ordnance Survey have made the decision to remove the bench mark values from their large scale mapping including OS MasterMap Topography Layer. The bench mark indicators do still appear on the maps, but as they have not been maintained or updated for many years and are out of date, OS are unable to guarantee the accuracy of the bench marks due to natural erosion, subsidence or relocation of the benchmark. Ordnance Survey do maintain a database of the old bench mark values, if you would like to know the value of a bench mark, or would like further information regarding the removal of bench mark values please click here to see the following page on Ordnance Surveys web site. To obtain a bench mark value from this page you will need the Ordnance Survey tile reference, minus its last two letters, to enter into the “KM Square” box on the OS web page. This will provide a list of all bench marks in the OS tile you have entered.
