A former animal research facility, outbuildings from the 1850s, and a crater where the Army blew up a mansion will be among the historical drawcards for South Australia's newest national park.

For the next few days the public can visit the site of what will become Glenthorne National Park, a 208-hectare former CSIRO property that will provide the final link in a 1,500ha wildlife corridor from the Adelaide foothills to the sea.

The State Government wants community input regarding the park's future, including revegetation programs, the creation of walking and bike trails, and tours of ruins and research buildings that have been off limits for decades.

"We want people to get in behind these locked gates over the next few days and tell us what their priorities are for this site," Environment Minister David Speirs told ABC Radio Adelaide's Mornings program.

Primate house 'a dark place'

The former CSIRO buildings include a primate house where monkeys were used for research. ( ABC Radio Adelaide: Simon Rose )

Overseeing the transformation is the Environment Department's Michael Garrod, who said the fenced-off research precinct included about 30 buildings that were used from 1949.

"The primate house is a pretty dark place with all these little cells set up," he said of the facility used for testing on animals.

"We worked, I guess, in different ethical times with different ethical standards.

"But the work that was done here was very valuable in terms of animal nutrition and crop production."

Gutted mansion blown up

Glenthorne's first European inhabitant was Thomas Shuldham O'Halloran, the state's first police commissioner, who arrived from Britain in 1838 to establish a farm, including wine grapes.

After the death of O'Halloran and his wife Lady Frances, their sons sold the site to Thomas and Jane Porter, who completed building a mansion there in 1880.

Flinders University landscape archaeologist Pamela Smith said it was a substantial building believed to be modelled on a house called Glenthorne in Devon, England.

The Porter mansion was gutted by fire in 1932. ( Supplied: State Library of South Australia (B 4928) )

"The Army took over Glenthorne in 1913, although they had a presence there from 1910," Dr Smith said.

"This was the remount depot where the horses left South Australia for World War I, and the history of this period represents a major contribution of South Australia to the war effort."

The Army remained at Glenthorne for the next 35 years, but activities there slowed between the World Wars as horses were gradually replaced by motorised vehicles.

"The house wasn't used much so it fell into disrepair, and unfortunately in September 1932 it caught on fire," Dr Smith said.

"The Army couldn't restore it because it was too badly damaged, and it was blown up with explosives.

"All that's left of the mansion is a depression in the ground and a big flat area where it was bulldozed."

There are, however, ruins of O'Halloran's outbuildings, many of which are on the state heritage register.

Ruins from the mid-1800s are reminders of the O'Halloran period. ( Instagram: little_miss_dee )

Government pledges 'no subdivision'

Threatened with subdivision since the CSIRO moved out in 1996, the Government is in the process of taking over the site from its more recent owners, the University of Adelaide, and has promised to return it in full to the community.

"We've had the Friends of Glenthorne fighting tenaciously for about 20 years to ensure that urban sprawl doesn't sweep over this site and we don't end up with a suburb called Glenthorne," Mr Speirs said.

"It's been saved."

Showcasing the site's heritage values and Indigenous history were all future options, Mr Speirs said, along with creating a major nature play site on land currently used for grazing.

"That's one idea that bubbles out of the community, and I think that's likely to get a guernsey — but what other ideas does the community have?"

It also represents a missing link between Happy Valley Reservoir, O'Halloran Hill Recreation Park and Marino Conservation Park, a wildlife corridor into which investment can be made towards rehabilitating the land.

"A lot of the land is already protected under the National Parks and Wildlife Act and is linked informally, but we want to create walking trails that link all this together," Mr Speirs said.

The Glenthorne property will contribute to 1,500 hectares of open parks and land in the region. ( Supplied: SA Government )

A 'wonderful outcome'

Friends of Glenthorne secretary and treasurer Alan Burns said he "almost could not believe" the Government was creating a national park having fought for it for many years.

"We felt we couldn't lose any of it for housing and it had to be preserved for the local area," he said.

"Our group was formed on a constitution that preserved that property and we've stuck to that and this is a wonderful outcome."

Mr Burns said the site included remnant grey box trees that were up to 500 years old and was already an important habitat for birdlife despite being "overcropped and overgrazed".

"It needs a proper habitat restoration program with a lot of it focused on native grasses and small native plants, herbs and daisies and that sort of thing.

"Once you have those established, you're controlling weeds, which saves a lot of money because you're not using labour or herbicides.

"You put down your carpet of native grasses and daisies and then we can put some bigger stuff in."

Mr Speirs said stock grazing would continue to play a role in managing weeds on the site until it was rehabilitated.

The site is open to the public from Friday to Sunday between 12:30pm and 4:30pm, with access off Majors Road at O'Halloran Hill.