A Hidden Landmark on Windmill Hill: Discover the Trig Point at Elmore Court Estate
At the loftiest point of Elmore Court Estate, perched high on Windmill Hill, lies a quiet relic of Britain’s surveying past.
Nestled into a field boundary, framed by hawthorn and dusted with lichen, stands one of the most quintessential features of our landscape heritage: the Trig Point.
Triangulation Points, commonly known as Trig Points, are an iconic sight across the British countryside. More than 6,500 were built throughout the UK in the 1930s by the Ordnance Survey, forming a vast network of interlocking triangles used to accurately map the nation. Their distinctive concrete pillars follow the “iceberg principle”, with a substantial mass hidden below ground to ensure stability.
Each Trig Point was designed to support a brass fitting known as a spider, mounted at the top of the pillar. This allowed surveyors to attach a theodolite - a precision instrument used to measure angles and distances. Positioned on hilltops and open landscapes with long sightlines, surveyors could see at least two other Trig Points on a clear day. By calculating the angles between them, they were able to produce remarkably accurate maps of Britain, plotting everything from field boundaries and roads to railways and infrastructure.
Look closely and you’ll find a metal plate set into the side of the pillar. This is the Flush Bracket, stamped with the letters OSBM (Ordnance Survey Benchmark) and a unique reference number. Using this number, the Trig Point’s precise location, height and coordinates can be identified. The Windmill Hill Trig Point stands 34 metres above sea level.
The rise of Trig Points was driven by the need for more accurate mapping following the rapid development that took place after the Great War. While modern satellite and drone technology has rendered them obsolete, Trig Points remain a powerful reminder of our relationship with the land and the craft of traditional map-making.
Many Trig Points have been lost over time due to erosion and development, making those that remain all the more precious. They often occupy places of outstanding natural beauty, offering panoramic views for walkers and inspiring the much-loved pastime of Trig-bagging, where hikers seek out and visit as many points as possible. Even today, Trig Points are still marked on modern maps with a distinctive blue triangle.
If you come and stay with us at Rewild Things, be sure to take a walk up Windmill Hill. You’ll be rewarded with sweeping views across the Severn Vale, a glimpse of our rewilding landscape in action and a tangible slice of British history quietly standing among the trees.
