Letters: Trig Points and Yes Minister

While historic trigonometric survey points across the United Kingdom have recently gained attention for their cultural and architectural significance, emerging research suggests these enduring structures may also offer unexpected benefits for public health, particularly in promoting physical activity and mental well-being through engagement with Britain’s rural landscapes.

Campaigners have called for the first and last Ordnance Survey trig points to be granted listed status, citing their role in mapping Britain and their place in national heritage. These concrete pillars, many erected in the mid-20th century, were instrumental in creating accurate maps of the country’s topography. Though their original surveying purpose has been superseded by GPS technology, the trig points remain embedded in the British countryside, often located in remote and scenic areas such as the Scottish Highlands, the Lake District, and the Welsh mountains.

One lesser-known detail about these structures is their construction method: the concrete for many trig points was poured into cardboard tubes manufactured by the Venesta company, a fact noted by a contributor from St Andrews, Fife, who recalled encountering such markers during hikes. These so-called “Venesta tubes” were designed for use in less accessible terrain, allowing surveyors to create stable foundations where traditional formwork would be impractical. While this detail speaks to engineering ingenuity, it also underscores how these markers are now encountered primarily by walkers, hikers, and outdoor enthusiasts.

Recent studies in public health have highlighted the value of accessible green spaces and structured outdoor activities in combating sedentary lifestyles, reducing stress, and improving cardiovascular health. According to the UK’s Office for Health Improvement and Disparities, regular participation in outdoor physical activity is associated with lower risks of heart disease, type 2 diabetes, and depression. Initiatives that encourage people to explore natural environments—such as hillwalking, mountain trekking, and long-distance walking routes—have been shown to increase adherence to physical activity guidelines, particularly among older adults.

Trig points, by virtue of their placement in elevated and often challenging terrains, serve as informal waypoints for hikers navigating by map and compass. The practice of “trig bagging”—visiting and documenting these survey markers—has grown into a niche but passionate hobby, with enthusiasts sharing routes, photographs, and logbooks online. This activity promotes not only physical exertion but also cognitive engagement, as participants must interpret topographic maps, estimate distances, and navigate variable weather conditions.

Mental health professionals have increasingly recognized the therapeutic value of “green exercise”—physical activity undertaken in natural environments. A 2023 systematic review published in Lancet Planet Health found that exposure to natural settings during physical activity was linked to greater reductions in anxiety and improved mood compared to equivalent exercise indoors. The sensory experience of being outdoors—combined with goal-oriented movement such as reaching a summit or locating a trig point—may amplify these psychological benefits.

Public health advocates note that leveraging existing cultural or historical features in the landscape can be a low-cost strategy to promote population-level physical activity. Unlike purpose-built fitness infrastructure, trig points require no maintenance beyond basic preservation and already exist in situ. Their integration into walking routes could be supported through updated Ordnance Survey maps, signage in national parks, or collaboration with walking associations such as the Ramblers or Mountaineering Scotland.

However, experts caution that promoting access to remote trig points must be balanced with safety considerations. Many of these markers are located in areas with unpredictable weather, steep terrain, and limited mobile phone reception. The Mountain Rescue England and Wales service advises that hikers undertaking such activities should carry appropriate navigation tools, wear suitable footwear and clothing, inform others of their route, and check weather forecasts before departure.

while the heritage value of trig points is widely acknowledged, their listing as protected structures remains under discussion. As of April 2026, no trig point has yet been formally designated as a listed building, though advocacy continues. Any such designation would need to balance preservation with public access, ensuring that these markers remain visible and accessible to those who wish to engage with them—not only as historical artifacts but as catalysts for healthy outdoor engagement.

In an era where public health strategies increasingly emphasize prevention and community-based wellness, the humble trig point offers a unique intersection of history, geography, and health. By encouraging people to explore the landscapes these markers helped define, they may continue to serve a purpose far beyond their original surveying function—one step, and one summit, at a time.