Fort Denison Port Jackson, New South Wales, Australia
By Geocaching Australia on 06-Mar-13. Waypoint TP6657

This passive Trig Point is the wind vane on top of the cupola of the light housing on the Martello Tower. This replaces Trig TS"L" that is still on the parapet and is now SSM22536. 

A trig point (also known as a Trigonometric Station) typically consists of a black disc on top of four metal legs or concrete pillar, resembling a navigation beacon. It is also accompanied by a metal disc, which is located directly below the center point of the tripod or on top of the pillar itself.

Trig points are generally located at the top of hills or points of prominence in the landscape. Many provide unique views and challenges, with some being difficult to get to.

These points were regarded as valuable to surveyors, providing reference points for measuring distance and direction, and assisting in the creation of maps.

You are encouraged to leave a description of your journey in your log to help others in finding the trig point.

The original collection of trig points has been sourced from Geoscience Australia and may contain inaccuracies.

Please respect local laws and regulations when searching for trig points. If you believe that a trig point is located on private property or in a dangerous location, you may archive the cache, by clicking on Log this Cache and place an "Archived" log on the Geocaching Australia website.

If you feel that you can add to the description of this trig point or adjust the difficulty / terrain ratings, please feel free to edit this cache and amend the information suitably. Vandalism of the cache description or other information will result in your account being terminated.