A trig pillar (we have no idea if this one will feature!). Photo: Bob Smith Photography

Trig-baggers have a chance to pocket £1,000 prizes if they can hunt down mystery pillars.

Ordnance Survey is running a social media challenge each Saturday during August, with a grand reward for the first sleuth to find a selected trig point.

The national mapping agency will broadcast a live stream from a different triangulation pillar somewhere in England, using its social media platforms on Instagram, TikTok and Twitch, prompting a race to find the pillar in question. Throughout the morning, clues will be shared on social media to help people track down that day’s trig pillar.

An OS spokesperson said: “The first person to arrive at the trig pillar and shout ‘Touch Grass’ to the camera will receive a £1,000 prize.

“OS is encouraging everyone in the UK to stop doom-scrolling social media feeds and take action to get outside instead.”

The government-owned company says its consumer research has found younger generations are less likely to engage with the outdoors because they are unfamiliar with, or lack confidence, using outdoor kit and mapping.

OS launched its Touch Grass campaign to address this. It said it has embarked on a series of ideas to gamify the outdoors through social media to attract more young people and promote how outdoor activities can be enjoyable.

During each weekend, unusual activities will take place at the mystery trig pillar while an OS champion waits for the first visitor to arrive.

Nick Giles, OS's managing director for leisure . Photo: Bob Smith Photography

OS’s managing director for leisure Nick Giles said: “We are always looking for ways of connecting with people to encourage them to experience more of the outdoors in Britain.

“Often our trig pillars are destination points or a great place to take a picture, but now for four lucky people visiting one could also win you a fantastic prize each week.”

Trig pillars are a network of four-foot-high stone obelisks that OS began erecting in the 1930s to improve its mapping of Great Britain. About 6,500 were constructed over the country for triangulation, a technique to obtain accurate locations for maps.

Surveyors used to place their equipment on top of them but they fell out of use in the 1960s when more modern mapping techniques were introduced, but thousands remain across the nations as monuments from the past. On an OS Map they appear as a blue triangle symbol with a dot in the middle.