Ordnance Survey celebrates 80 years of the trig pillars that helped map Great Britain. ... This is Worcester Beacon trig pillar at sunset, photographed by Dan Grant.

Ordnance Survey celebrates 80 years of the trig pillars that helped map Great Britain. ... This is Worcester Beacon trig pillar at sunset, photographed by Dan Grant.

On 18 April 1936, a group of surveyors gathered around a white concrete pillar in a field in Cold Ashby, Northamptonshire, and began the retriangulation of Great Britain. Ordnance Survey (OS) is ...