Trig-pointing (original) (raw)

Trigonometrical stations, commonly referred to as trigs, are fixed survey points placed at the highest peak of a mountain or hill. Often visible to at least two other surrounding trigs, they form a network of triangulations.

The characteristic white metal quadripods with black discs were installed in the 1970s as part of the ACT Precision Zone, and formed part of a national geodetic survey. The ACT Precision Zone and its associated marks have been the main surveying infrastructure for all new development in the ACT since the early 1970s.