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What Are Trig Points?

In the United Kingdom, trig points are usually concrete pillars, originally erected by Ordnance Survey starting in 1935. Their purpose? To aid in the accurate retriangulation of Great Britain. These iconic structures were placed on prominent hills and mountains and are now part of the landscape for walkers, hikers, and explorers.

10 Fascinating Facts We Love About UK Trig Points:

1. Trig points are typically concrete pillars set up by Ordnance Survey.

2. Most are cast concrete, but some are built from local stone.

3. Like an iceberg, there’s often more trig pillar below the surface than above!

4. There are exactly 6,190 trig points across the UK.

5. The highest trig sits atop Ben Nevis, Scotland’s tallest peak.

6. The lowest is at Little Ouse, at -1m below sea level.

7. In Scotland, some trig points are known as Vanessas – taller, cylindrica

   

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9. The very first trig pillar was installed on April 18, 1936, in Cold Ashby, Northamptonshire.

10. Trig points are marked with a small blue triangle on OS maps.

11. Trig pillars have become a target for “trig-baggers” – hobbyists who travel the UK to find and log them all!

So… What Is Trig Bagging?

Trig bagging is the fun challenge of visiting and logging trig points, just like peak bagging or geocaching. Whether you want to:

• Tick off all the trigs in your local area

• Complete all the trigs on a specific OS map

• Or set yourself a daily trig-challenge to walk, run, or cycle to several in one go...

There’s a trig adventure waiting for you!

This is a brilliant family-friendly activity, especially if you choose trigs on smaller hills. Let your Little Trekkers guide the way using map and compass—it’s a great way to learn navigation and explore the countryside.

Will You Join the Trig-Bagging Fun?

Start spotting, climbing, and collecting these historic pillars—and don’t forget to tag us in your adventure pics using #spottyotter!

Ready, set, bag those trigs!