Triangulation station
A triangulation station is a fixed surveying station, used in surveying.
It may also be known as a triangulation pillar, trigonometrical station, trigonometrical point, trig station, trig beacon or trig point, and sometimes informally as a trig,
The names of triangulation stations vary regionally; they are generally known as trigonometrical stations in North America, trig points in the United Kingdom, New Zealand and Australia, and trig beacons in South Africa; triangulation pillar is the more formal term for the concrete columns found in the UK.
Triangulation Station Media
The triangulation point on top of Mount Washington in New Hampshire
Class 3 triangulation point in Shiroyama Park in Inagi, Tokyo
Trig beacon on the summit of Lion's Head in Cape Town
A trig point near Wootton Wawen, Warwickshire, England
Trig point on Mam Tor, Derbyshire, England