Trig stations (or Trigonometric Stations) were critical to surveyors in providing reference points across Australia as they mapped the country. Thousands of trig points were generally sited on the highest and most prominent point in the local area, which means they often provide a great view – although many are now surrounded by trees and bushes. The trig stations or trig points typically consist of a black disc on top of four metal legs or a concrete pillar, while older ones consist of a rock cairn supporting a post and vane.

About a third of trig stations are located on government land; the map and list below are focused on those in and adjacent to national parks and nature reserves. This is very much a “work in progress”: having recently discovered the prevalance of these mostly hidden sites, I’ll add more trig points as I find time to reach them! If I’ve missed any in a national park or you’ve got a favourite, please leave me a comment at the bottom!

MAP KEY
Blue - a trig station referenced from SIX Maps
Green - trig stations I've visited and documented - see below
Orange / Red - trig station difficult to reach / located on private land & not publicly accesssible

Ku-ring-gai Chase National Park (Sydney North)

There are at least 30 trig stations across Ku-ring-gai National Park; most require a bit of off-track scrambling. The most challenging trigs, like Want Trig, require most of the day to traverse the thick scrub.     

	TS638 ARDEN (191m) Trig station is partly “unpiled”, but offers great views over West Head and out to Pittwater and the Barrenjoey Peninsula. Even better views from the rock platforms on both sides of the trig point. Distance: 3.8km return. Ease of Access: Moderate/Hard (no track) View: Great views from trig station and nearby rocks History: Non available Location: 33°38’02.9″S 151°15’03.4″E. Access via Waratah Track (400m off-track) More info: Rediscovering the Waratah Trail and Geocaching Australia
	TS649 ARTHUR (198m) The trig station is stil in pretty good condition; it is located just off a rough bushwalking track that goes from the Perimeter Trail out to Mount Murray Anderson. Distance: 3.1km return. Ease of Access: Moderate (narrow track) View: None from trig station History: Non available Location: 33°38’53.5″S 151°11’47.5″E. Rough (unmarked) track off Perimeter Trail. More info: Mount Murray Anderson bushwalk & Geocaching Australia
	TS681 BAIRNE (183m) It’s bloody hard work on a very rough and overgrown track through thick scrub up to the stone cairn and trig, which is still in good condition. Distance: 4.2km return. Ease of Access: Hard (very indistinct track & thick scrub) View: None from trig station History: Built 1883, last inspected April 1974 Location: 33°40’12.5″S 151°09’42.0″E. Rough (unmarked) track off Bairne Trail. More info: Bairne Trig bushwalk & Geocaching Australia
	TS1013 BOBBIN (185m) Not far off the Bobbin Head Trail, through some light scrub, is the Bobbin Trig Station. It’s partly demolished, although much of the stone cairn remains. Distance: 4.8km return (from Bobbin Head road). Ease of Access: Moderate View: None from trig station History: Built 1883, last inspected October 1979 Location: 33°36’50.6″S 151°17’09.9″E. Access from Bobbin Head Road or Bobbin Head More info: Sphinx to Bobbin Head loop bushwalk & Geocaching Australia
	TS1672 COWAN (197m) A short “bush bash” from the Cowan Track to this trig station, which is still in good condition but well-hidden in the scrub. Distance: 5.8km return. Ease of Access: Easy/Moderate View: None from trig station or nearby History: Last inspected: June 1982. Location: 33°39’10.8″S 151°10’28.2″E. Short bush-bash from Cowan Track More info: Cowan & Wilkin Tracks & Geocaching Australia
	TS1955 ELLIS (197m) An easy walk up the “Ellis Trig Trail”, which leads to a great lookout over Coal & Candle Creek. The trig station itself is a bit further up the hill – and there’s not much of it left! Distance: 0.3km return. Ease of Access: Easy View: Great views from just below trig station History: Last inspected: June 1983 Location: 33°38’52.9″S 151°13’44.9″E. Ellis Trig Trail from General Sam Martin Drive More info: Geocaching Australia
	TS2427 HARVEY (199m) Easiest access is by walking around the eastern side of the rock outcrop until you can scramble up to the top. There are remains of the old stone trig, and a newer steel post. Nice district views from the edge of the large rock platform. Distance: 0.8km return. Ease of Access: Moderate (no track) View: Nice views over Duffys Forest History: Built 1882, last inspected June 1983 Location: 33°40’10.3″S 151°14’03.7″E. Access from McCarrs Creek Road. More info: Geocaching Australia
	TS2531 HUNGRY (197m) A tough walk through thick undergrowth from the Hungry Trail to reach this trig station above General San Martin Drive. The base of the trig is still there, but missing post and vanes, and no views from the trig station. Distance: 0.5km return. Ease of Access: Hard (no track, thick scrub) View: Nice views from near trig History: Last inspected June 1983 Location: 33°39’18.7″S 151°13’39.4″E. Access from General San Martin Drive More info: Geocaching Australia
	TS2581 JACOMB (168m) Accessed via the Jacomb Trail (firetrail) with short off-track section through the bush, the Jacob Trig Station is mostly depiled and looks more like a pile of stones… Distance: 2.6km return. Ease of Access: Moderate View: No views History: Last inspected November 1973 Location: 33°41’00.8″S 151°09’41.3″E. Access from Bobbin Head Road More info: Geocaching Australia
	TS2882 LONG (208m) One of the few trig stations that is actually on a bushwalking track – or in this case, visible from the Long Trail and accessible by a short and distinct track. Distance: 7.6km return from end of Cullamine Road. Ease of Access: Moderate View: No views (continue 900m to end of Long Trail) History: Last inspected January 1973 Location: 33°38’13.7″S 151°10’37.2″E. Access from Long Trail More info: Long Trail bushwalk & Geocaching Australia
	TS3015 MCCARR (196m) A short scramble up from West Head Road brings you to some nice rock formations with views over Coal and Candle Creek to the west. The trig point is a bit further away from the road and is in poor condition. Distance: 0.5km return. Ease of Access: Moderate (no track) View: None from trig. Nice views from closer to road. History: Built 1882, last inspected October 1978 Location: 33°39’07.4″S 151°15’40.7″E. Access from West Head Road. More info: Geocaching Australia
	TS3018 MCCOWEN (184m) Accessible from the Chiltern Trail or from Chiltern Road, a short climb gets you to the trig station. There’s only a glimpse of the ocean from the modern concrete pedestal, but some nice views of Coal and Candle creek to the north-west from just below the trig. Distance: 1.4km return. Ease of Access: Moderate (no track) View: Nice views from rocks below trig. History: Non available Location: 33°40’09.8″S 151°15’50.4″E. Access from Chiltern Trail or Chiltern Road More info: Chiltern Trail bushwalk & Geocaching Australia
	TS3914 ROACH (223m) One of the highest trig points in Ku-ring-gai Chase NP, just 10m below Willunga – but absolutely no view! A short but tough bush to this forlorn circle of rocks, that once was a cairn. Distance: 4.8km return. Ease of Access: Moderate View: No views from trig. History: None available Location: 33°39’00.5″S 151°10’57.9″E. Just off Long Trail in thick scrub More info: Long Trail bushwalk & Geocaching Australia
	TS5929 TABER (204m) An easy walk up from Cottage Point Road via a walking trail to the trig station, which has been damaged by bushfire. Continue 100m for a great view over Coal and Candle Creek. Distance: 0.4km return. Ease of Access: Easy View: No views from trig. Continue 100m for great views. History: Last inspected August 1977 Location: 33°37’51.3″S 151°12’28.2″E. Access via Ausgrid access trail More info: Trig Bagging at Cottage Point  & Geocaching Australia
	TS4625 WARATAH (182m) Stunning views over Coal and Candle Creek from the trig station and from “Paddys Castle” 150m to the south. Unmarked access track from Waratah Trail Distance: 7km return. Ease of Access: Moderate View: Great views History: Buily 1882; last inspected January 1973 Location: 33°37’46.0″S 151°13’48.5″E. Access track from Waratah Trail More info: More info: Rediscovering the Waratah Trail and Geocaching Australia
	TS4763 WILKINS (195m) Located close to the Perimeter Trail, the trig station is missing its post or vanes, and is surrounded by trees – so no views in any direction. Distance: 4.4km return. Ease of Access: Moderate (no track) View: No views. History: Last inspected June 1982 Location: 33°39’23.6″S 151°12’07.9″E.  Access track from Waratah Trail More info: Geocaching Australia
	TS2779 WILLUNGA (233m) Willuga Trig is the highest point in Ku-ring-gai Chase National Park, and offers great views toward Pittwater and as far as the city of Sydney to the south. Distance: 1.5km return. Ease of Access: Easy View: Great views History: Last inspected December 1972 Location: 33°37’46.0″S 151°13’48.5″E. Take Willunga Trail from West Head Road More info: Willunga Trail bushwalk & Geocaching Australia

Muogamarra

Muogamarra Nature Reserve is only open to the public for six weekends a year (usually over August & September). It contains two trig stations; the track to LLoyd Trig is a popular bushwalk when the nature reserve is open. 

TS2871 LLOYD (210m) A short walk to a trig point with views over the Hawkesbury River as well as toward West Head and Barrenjoey. Distance: 2.8km return. Ease of Access: Easy View: Great views History: Last inspected October 1982 Location: 33°32’48.1″S 151°11’27.4″E. Take Lloyds Trig Track More info: Lloyd Trig bushwalk & Geocaching Australia

Brisbane Water National Park

Unlike Ku-ring-gai Chase National Park where almost all the trig points are off-track and out-of-sight, in Brisbane Water National Park some are local attractions. Both Warrah Trig and Wondabyne are the destination of two popular bushwalks.

TS5606 WONDABYNE (251m) Outstanding 360-degree views from this trig point on top of Mount Wondabyne: sweeping views toward Woy Woy and the surrounding central coast suburbs to the east, and Brisbane Water National Park and Wondabyne station to the west. Distance: 7.4km return from Woy Woy Road. Ease of Access: Easy View: Great 360-degree views History: Last inspected May 1985 Location: 33°29’38.0″S 151°16’30.0″E. More info: Pindar Caves and Mt Wondabyne bushwalk & Geocaching Australia

More Information

A Brief History of Trig Stations in NSW

The first or baseline trig station was established at Lake George in 1867 (TS778 Lake George) by the Trigonometrical Survey of New South Wales. The surveying efforts continued for almost fifty years until it was suspended to reduce cost at the outset of WWI, with about a third of NSW covered. The survey was resumed intermittently between the two World Wars predominantly by the Royal Australian Survey Corps, and by 1966 the geodetic network covered about half of the state. In 1973 a plan was formulated to revise and complete the network, starting in the SydneyNewcastle-Wollongong region and continuing along the coast and then westwards. Many old-style cairn and pole stations were replaced by a concrete pillar with demountable mast and vane. Eventually, over 6,000 traditional ‘passive’ trigonometrical (trig) stations were installed, now managed by NSW Land Registry Services.

The relevance of the traditional trig stations was significantly reduced by the introduction in 2009 of the Global Navigation Satellite System (GNSS) Continuously
Operating Reference Station (CORS) networks, or CORSnet-NSW. Covering all of NSW, CORSnet-NSW provides centimetre-level real-time positioning and allows nearby equipment and machinery to accurately determine coordinates for positioning and guidance solutions.

However, while it took only five years to cover more than two thirds of NSW with 150 active CORSnet-NSW trig stations by July 2014, passive control stations are still necessary. Consequently, the Land and Property Information (renamed the NSW Land Registry Services in 2017) initiated a process to select a subset of trig stations to maintain. Multiple criteria (including prominence within the survey network, ease of access, historical significance and monument quality) are used to assess each trig station across NSW and calculate a ‘TrigStar’ score out of 100 and a corresponding rating out of 5 stars. Based on this rating, the top 500-700 (about 10% of the total) will be maintained.

Read more: Preservation and Upgrade of Trigonometrical Stations in NSW [PDF]

Trig Station status

Some trig stations have a letter after the trig station code – this provides additional information on the trig station or survey mark:

Code	Status	Description
D	Destroyed	Evidence was found that the mark is destroyed
F	Found	Mark was found in good condition
N	Not Found	Mark was searched for, not found, but no evidence exists to indicate that it was destroyed
R	Restricted	Mark is in a restricted area and requires special permission for occupation.
S	Subsidence Area	Mark is located in an area identified as being subject to movement
U	Uncertain	Mark was found, however it was in an unstable condition or there was evidence that it had been disturbed or moved.

Resources

There’s a surprising amount of details on most of the trig stations, with their locations and inspection reports publicly available:

• SIX Maps provide access to a range of NSW primary spatial data – check the “Survey Marks” box to view trig stations (TS) as well as State Survey marks (SS) and Permanent Marks (PM)
• Survey Mark Sketches show the physical position of numbered Survey Control Marks (enter the number only, not the TS prefix to download a report)
• Geocaching Australia has thousands of trig stations registered as “virtual caches”, with additional information and useful access comments in the logs. There are also maps available, such as this one of all Australia trig station geocaches.

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