[1] Many thousands of such engravings are known to exist in the Sydney region, although the locations of most are not publicised to prevent damage by vandalism, and to retain their sanctity, as they are still regarded as sacred sites by Indigenous Australians.
[5] The engravings were made by the Aboriginal Australians who have lived in the Sydney region from about 30,000 years ago until the present day.
Radiocarbon dating suggests human activity first started to occur in the Sydney area from around 30,735 years ago (28,724 BCE).
In support of this, it is true that rock art elsewhere (e.g. Kakadu National Park) does show extinct animals, and so must be tens of thousands of years old.
[11] While their purpose is not known definitively, some educated guesses may be made by analogy with the culture of other indigenous groups who survived into modern times, as follows.
Some sites also show evidence of Aboriginal Astronomy, as the rock's patterns resemble the Milky Way and this may have been purposed as an astrological guide.
[12] The aboriginal rock engraving sites usually contain images of sacred spiritual beings, mythical ancestral hero figures, various endemic animals, fish and many footprints.
[13] Les McLeod, a local indigenous guide in Hawkesbury stated, “A lot of Aboriginal people believe they were created from animals – there are engravings here of wallabies, fish and emus”.
Rock painting illustration usually feature humans, kangaroos, emus, echidnas, grid patterns, animal tracks, boomerangs, axes, hand stencils, among others.
[15] Rock engravings in Sydney would usually feature fish, animals, humans, wooden artefacts, and mythological beings.
Dug wells in the Sydney region were used by the local tribe to sharpen tools and also as a source of fresh drinking water.