There are a handful of trig stations in Marramarra National Park, some close to walking but many on rugged and hard-to-reach ridges. There are many more trigs around the park, but these are often on private land or public access is not possible. A number of trigs in this area have also been destroyed over time.
See also Trig Stations in Sydney’s North – which includes trigs in national parks and those scattered throughout the suburbs…
Coba Trig in Marramarra National Park is reached via a route that's partly on a firetrail, and partly off-track. Only the stone cairn remains.
Denny Trig is a traditional stone cairn trig, with mast and vane almost completely destroyed. A very short detour on the bushwalk to Coba Point.
The Fagan Trig along the Peebles Trail is partly damaged, despite the stone cairn being cemented.