Trig Stations are permanent survey marks situated at the top of high hills and mountains.
They form part of the Geodetic Survey Network, supported in NSW by Land Property Information.
Some are substantial concrete structures or huge stone cairns supporting a column & disc. Others are simple survey marks embedded in concrete.
Unfortunately all the trigs stations I have seen mounted on stone cairns are delapidated.
When the Trigs were constructed the area surrounding them was cleared so they could be seen from trigs on nearby hills.
Over time, many of these clearings have been overgrown, in places by almost impenetrable montane heath.
Even though Trigs have build in high places with locations clearly marked on a map they may be difficult to find.
Where once there would have been excellent views from the Trig there may be no view at all now.