Trig Point
Short for "Triangulation Point" (also known as a Benchmark) this is the detail from an Ordnance Survey triangulation pillar on top of Abbotsbury Castle, Dorset. On the O/S Explorer Map for the area, the pillar is marked by a small blue triangle with a blue dot in the middle. In this case, the map shows the height above sea level as 215 metres.
Even though the mapping use of these has been superceded by satellite and laser technologies, hundreds, possibly thousands of trig points remain in situ across the UK.
Trig Point
Short for "Triangulation Point" (also known as a Benchmark) this is the detail from an Ordnance Survey triangulation pillar on top of Abbotsbury Castle, Dorset. On the O/S Explorer Map for the area, the pillar is marked by a small blue triangle with a blue dot in the middle. In this case, the map shows the height above sea level as 215 metres.
Even though the mapping use of these has been superceded by satellite and laser technologies, hundreds, possibly thousands of trig points remain in situ across the UK.