This week is Trig Point Week.

If you've ever gone hiking in the UK, you may have noticed a small, concrete pillar on a hilltop or ridge. This is a trig point, short for "triangulation point." These unassuming structures played a crucial role in mapping and surveying the country, and they continue to be a useful navigational tool for hikers and mountaineers today.

Trig points were first established in the 1930s as part of the retriangulation of Great Britain, a project to create a more accurate map of the country. The idea was to use a network of points, each with a known location and elevation, to triangulate the position of other features on the landscape, such as hills, buildings, and rivers. This allowed cartographers to create more detailed and accurate maps, and also served as the foundation for the Ordnance Survey, the UK's national mapping agency.

The trig points themselves were designed by a man named Brigadier Martin Hotine, who was tasked with creating a structure that was sturdy, easy to transport, and could be set up quickly on a variety of terrains. The result was a simple, three-legged structure made of reinforced concrete, standing about four feet tall. The top of the pillar was marked with a brass plate, known as a flush bracket, which surveyors could use to take measurements and calculate distances.

In total, over 6,500 trig points were constructed across the UK, with the majority located in England and Wales. The network covered nearly every corner of the country, from the remote hills of the Scottish Highlands to the flatlands of East Anglia. Each trig point was given a unique number, starting with TP1 in Cold Ashby, Northamptonshire, and ending with TP7145 on Mount Battock in Scotland.

While the use of trig points for mapping declined with the advent of GPS technology, they remain a popular landmark for hikers and mountaineers. Many trig points are located on high points with stunning views, making them a popular destination for outdoor enthusiasts. Some hikers even make it a goal to visit as many trig points as possible, with the Ordnance Survey offering a special badge to those who have visited at least 20.

Trig points have also become a cultural icon, appearing on everything from T-shirts to tea towels. They even have their own fan club, the TrigpointingUK community, which has catalogued and documented every trig point in the UK and encourages others to do the same.

In conclusion, trig points may seem like a simple structure, but they played a vital role in mapping and surveying the UK. Today, they continue to serve as a useful navigational tool and a popular destination for hikers and mountaineers. Whether you're a seasoned trig pointer or just starting out, these humble pillars are a reminder of the ingenuity and perseverance of those who came before us