This historic Mount Gilead Estate was officially added to the State Heritage Register this week.
The property, located along Appin Road at Gilead, south of Rosemeadow, has a considerable Indigenous and colonial significance.
The now heritage-listed 150-hectare estate is not part of the neighbouring housing development - Figtree Hill - being created by Lendlease on the Mount Gilead paddocks.
Don Harwin, the state minister responsible for heritage, highlighted several aspects of the historic property which made it worthy of heritage listing.
"Mount Gilead Estate is an outstanding early 19th-century colonial estate with a spectacular sweeping landscape," he said.
"Its heritage buildings have inspired celebrated artists and photographers throughout the 19th and 20th centuries and we're excited to list this site on the State Heritage Register.
"Features of the estate include the original dwellings of its residents and workers, such as the historic homestead, stables, outhouses and sandstone granaries, which have not changed substantially since the early 19th century.
"The estate's artificial lake and sandstone mill tower (c.1836) are rare and early examples of their type in NSW and Australia."
The property's listing on the State Heritage Register also details evidence of Indigenous activity on the land.
"The south-western areas of the estate feature swing pivot irrigation paddocks on the flats near the Nepean River," it read.
"These paddocks are edged in stands of indigenous trees and form a visual barrier in views south-west and west from the homestead and mill tower. The landscape also reveals evidence of the Dharawal people's past occupation and use of the land, with art sites, rock shelters, artefact scatters and potential archaeological deposits primarily concentrated along the vegetated gullies and waterways of Woodhouse and Menangle creeks."
The Save Mount Gilead Inc Facebook page posted of the group's desire for the entire Mount Gilead property - not just the historic homestead estate, but also the farm and paddocks, where Lendlease's development will be constructed - to be included on the register.
"There are many yet to be discovered aspects of Mount Gilead to be found," the post read.
"This is better than nothing. [It's been] four years since the listing was submitted, over 12 months ago it was accepted, yet it was 12 months before it was gazetted."
State environment minister Matt Kean said Mount Gilead Estate was also home to one of the state's healthiest koala populations, and the heritage listing would provide further protection for the fluffy marsupials.
"Just as the way we treat our koalas is a reflection on how we respect the environment, the way we treat our heritage buildings reflects how we respect the past," he said.
"It is vital we pull out all stops to not only protect habitat but also the structures that help us define who we are as Australians."
The estate is three figures considered of great importance in the development of NSW: Reuben Uther, Thomas Rose and Edward Woodhouse. All three made 'lasting contributions' to the country's agricultural development.
The heritage listing described Mount Gilead as "an early 19th century colonial estate with rare surviving features and outstanding picturesque qualities".
"It forms one of a continuum of notable colonial properties along Appin Road," the statement of significance read.
"Mount Gilead provides intact evidence of the colonial expansion into the Camden and Campbelltown areas south-west of Sydney in the period 1810-1840 and its development throughout the 19th century, including changes in agricultural pursuits and approaches to estate planning.
"Extant structures and landscape features, such as the artificial lake, sandstone granaries and homestead group, sandstone mill tower, mature plantings and archaeological sites have the potential to reveal evidence of how colonial estates were planned and developed, as well as the domestic and working lives of its residents and workers, and Aboriginal occupation and use of the land prior to its colonial development."
The new listing will ensure that the estate's significance will be protected for future generations, with any major proposed changes now requiring the approval of the Heritage Council of NSW.