What are Triangulation Pillars?

The concrete structures on mountain tops are triangulation pillars or trig pillars. Abigail and Joseph wondered what they were used for and found out they were important tools for mapping.

Historical Importance

Triangulation pillars marked the highest points of land and were used to create maps. The first trig pillar was used on April 18, 1936. Abigail and Joseph aimed to visit 90 trig pillars before the 90th anniversary.

The Adventure Begins

Abigail and Joseph started their challenge on April 18, 2025, and aimed to visit 90 trig pillars in a year. They traveled on weekends and school holidays, even using Christmas Day and Abigail's birthday for their challenge.

Favorite Moment

Abigail and Joseph's favorite moment was climbing Snowdon Mountain before sunrise. Sometimes, trig pillars were hidden by bushes, but they managed to visit six in one day in the Peak District.

Technological Advancements

Each trig pillar is about 1.2 meters tall, with most of it hidden underground. The Ordnance Survey (OS) installed these pillars, which played a crucial role in mapping. However, with technological advancements, more modern methods are now used. OS Field Surveyor Alfie Turner explained that they use GNSS receivers for precise measurements and updates for 3D positioning and boundary mapping.

Conclusion

Abigail and Joseph visited 89 trig pillars and are waiting for their last day to reach the 90th. This challenge taught them about the methods used to create maps and showed them how technology has advanced. This story can spark children's curiosity and teach them about geography and technology.