It's littered with basalt and dolerite boulders and tall yellow box eucalyptus trees.

"It's a beautiful spot," Mr Watson said.

Little did he know his property was home to an old Aboriginal quarry, making it one of the most significant archaeological finds in the capital region.

"It just felt good. I had no idea really what it was," he said.

Mr Watson hosted a ceremony on his property last month, with the site officially recognised as an Aboriginal Place.

It's part of a NSW government program which sees Indigenous custodians and contemporary landowners financially reimbursed for hosting tours and visits to declared sites, while protecting their values.

The discovery was made in 2016, after one of his sons invited his friend, Aboriginal archaeologist David Johnston, out to the site.

"He quickly realised what it was. It only took a few minutes," Mr Watson said.

"He was quickly excited and eventually saying it was the most significant archaeological discovery in our region for decades."

Mr Johnston spent the next few years fighting to have the site officially recognised as an Aboriginal Place.

Aboriginal people used the site to make stone axe heads with the dolerite, trading the precious mineral at big gatherings like bogong moth feasts.

Mr Johnston said these quarries were a "prize" for whoever had them.

"We've always known there was these wonderful axes, but we didn't know where they came from," he said.

The axes were used to make everything from boomerangs, canoes, shields and spears.

He said a lot of similar quarry sites had long been destroyed, but finally a whole one had been found intact.

"It's a wonderful spot. The hill there would have been used as a pathway and a spotting, vantage point," he said.

He said when he arrived at the site he noticed the rocks all around were chipped.

"It just dawned on me that these are all stone tool artefacts that could only be made by people," he said

He told Mr Watson that before he could do anything else, he would have to bring in local Ngunnawal elder Uncle Wally Bell and Ngambri elder Aunty Matilda House.

It was the beginning of a "beautiful" relationship between Mr Watson and the elders, Mr Johnston said.

"They're very friendly and warm," Mr Watson said.

"Both Matilda and Wally said 'Look, landholders have nothing to fear. This is not the first step in a land rights claim, put that away from your mind'."

Mr Johnston said a "racist myth" had been perpetuated by the government and media that landowners and Indigenous custodians couldn't work together. He hoped the program would change that.

"We thought one of the ways to bring Australians together is a shared history," he said.

Mr Watson said he would love to keep building a relationship with local Indigenous people.

"The whole family - my children, my wife - we recognise the wrongs of the past. The dispossession. We see this as an opportunity to just make this small gesture towards reconciliation."