More than 100 people are expected to descend on a Wollombi property to observe a celebration of culture featuring traditional dancing around an open fire.

Regarded as a crucial link in keeping Aboriginal customs alive, the corroboree is marking its 20-year anniversary.

Ngemba tribe member, dancer Andrew Snelgar, of Raymond Terrace, said more than 70 dancers from about eight tribes would take part.

"Dancers from across NSW and interstate will be painting their bodies and wearing traditional indigenous clothing on the night to invigorate the spirit of the land," he said.

Entry to the corroboree is free and open to all. It is a chance for non-Aboriginal people to experience the culture up close.

Gates to the property, at 2579 Paynes Crossing Road, open at noon. Dancing begins at dusk.

Camping and alcohol are not permitted.

Some food and soft drinks will be on sale but people are encouraged to bring a picnic.