Calga lies within the traditional lands of both the native Darkinjung and Kuringgai peoples and is an Aboriginal word meaning "the mouth". The locality's main feature is the state heritage-registered Aboriginal women's site, whose highlight includes the site of a sandstone amphitheatre.
Population
In the 2021 Census, there were 134 people in Calga. 79.1% of people were born in Australia and 88.1% of people spoke only English at home.[1]
Heritage listings
Calga has a number of heritage-listed sites, including: