Hill Top principal Mark Gardiner said the NAIDOC celebration was part of an Education Week open day for parents and the community.

The open day included a Welcome to Country, smoking ceremony, unveiling of Dreamtime story murals, a movie of the mural-making, and barbecue. The murals of Mirrigan and Gurrangutch, a Dreamtime story of how the Southern Highlands formed, were painted by students and a local Indigenous artist, Uncle Peter.

"You get reports twice a year and parent-teacher interviews, so you get something written on paper, and mum and dad have a chat," Mr Gardiner told the assembled students.

"But very rarely do you get a chance to say, Wow! Look at our school, isn't it great? And it is a great school and a great community," Mr Gardiner said.

Students Brendan, Kiara (Years 6) and Jessie (Year 2) also spoke at the special assembly, which included local elders, education officials and Clr Larry Whipper.

Brendan said the school had this year "focused on enriching the classrooms with activities that promote positive behaviours for success and engagement in learning".

Jessie said the positive behaviours included "respect, responsibility and cooperation", and that the movie of the mural-making showed those values in action at Hill Top.

Kiara said it was great to see Indigenous and non-Indigenous children "planning, drawing, creating, filming and working together to get our project completed".

Velma 'Aunty Val' Mulcahy said Mirrigan had chased Gurrangutch, who "could turn into a fish, or a snake, and bury down under the ground."

Mirrigan had chased Gurrangutch from the Blue Mountains to Wombeyan Caves, carving out the Wollondilly and Wingecarribee rivers along the way.

The gathering had another important moment for Aunty Val, who recognised a heritage hall on the school grounds as a classroom of her youth.

"I went to school in that [hall] in 1940 at La Perouse," Aunty Val said. "It was part of the Aboriginal school. That building was brought here in 1950. So it's good to come home."