A structure on top of a hill, usually coloured black and white, used as a physical reference point by surveyors to determine location. The symbol shown on the map includes the elevation and trig identification code for beaconed trig stations.
These topographic trig points are derived from New Zealand geodetic marks data which can also be accessed through the LINZ Data Service: NZ Geodetic Marks and NZ Geodetic Vertical Marks.
Data Dictionary for trig_pnt: https://docs.topo.linz.govt.nz/data-dictionary/tdd-class-trig_pnt.html
This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.
Further information on Topo50:
http://www.linz.govt.nz/topography/topo-maps/topo50