Trigpoints are the common name for “triangulation pillars”.These are pillars of usually about 4 foot in height which are dotting about the country, their original purpose was for ordiance survey to determine the exact shape of the country. The network of triangulation pillars, which started to appear in the 1930s, led to the OS maps which we all use today.
They are generally located on the highest bit of ground in the area, so that there is a direct line of sight from one to the next. This makes them a great item to use as a progress marker when trying to bag summits.
Nowadays, most of the monuments described above have fallen into disuse. However a number of the old triangulation pillars and FBMs, along with various newly installed bolts and rivets, now form the “Passive Station” network. THis network is made up of about 1000 pillars, but there are even more that are no longer in use but still exist and are a commonly seen sight in the photographs of hikers.
There are 25598 trigpoints within the UK (if we include everything that could be classified under that meaning), at first though I aim to visit all the historical pillars with is a more managable 6190. Wish me luck 😀