Triangulation Station

I took a friend for a walk from my house, up into the hangers (wooded slopes). I photographed a horse rolling, some super views, the poets stone (Edward Thomas), trees, and tree roots covered in moss, but decided on this shot for my blip. The sun was setting when we reached the top where this trig point is sited.
This is a fixed point from where the surveying can be done. They are usually on prominent hills and mountains and were erected by the ordnance survey. Their function has been largely superseded by aerial photography and digital mapping.