Trig points or Triangulation Pillars are another way of spotting the top of a mountain on a map. The symbol for a trig point is a small triangle. They are real concrete pillars that are placed at particular places which are usually the tops of hills or mountains.

Where are the trig points in the UK?

Trig pillars are often on peaks of hills, as George Ewen's photo from the cover of OS Explorer map for Crieff, Comrie and Glen Artney, Perthshire, shows. But the lowest, at Little Ouse, Norfolk, sits at 3ft (1m) below sea level.

What is the meaning of trig point?

noun. a point used in triangulation as a basis for making maps. Triangulation stations are marked in a number of ways, such as by a tapering stone pillar on a hilltop. Also called (informal): trig point or (Austral.