80 Boronia Parade Lugarno has been held by the same family since 1908 and has been untouched at more than 25,400 square meters.
Historical records show that the villa was purchased from Sydney City Bank some 80 years ago and the property has since been used for oyster farming and the sale of fruit and vegetables to the local community.
The site was listed for sale in May last year, however, a temporary heritage order was put in place - removing the proposed subdivision of the site into a residential area.
At the time the property was listed, it was valued at approximately $10 million.
The waterfront property, nicknamed "Glenlee", located 25 minutes south of Sydney's CBD, includes a private marina and a boat shed.
The property is being offered for sale with intent through One Commercial agents Joshua Charles and Simon Kent, with offers due to close on July 13.
Mr Charles said the property would provide a great opportunity for a private waterfront family estate or to create a development for investors.
"It would be impossible to find a property like this anywhere in downtown Sydney.
Mr Charles said the property would provide a great opportunity for a private waterfront family estate, or create a development project for investors.
"Imagine the incredible family home or estate that could be built on such a large piece of land. If this was in the eastern suburbs of Sydney, it would be at least 10 times more expensive.
"We expect interest from retirement living operators, church groups and schools looking to use it as a potential retreat, individuals looking to enjoy country living in the city, and of course developers."
In 1920, the property was subdivided and Boronia Parade was built. Since then, a large portion of the land has been cleared, containing Boronia Parade and three entrances on Ballanda Ave.
Locals are calling on the council and state government to acquire the Lugarno property and take it out of private hands, and more than 600 people have joined a public Facebook group, "Save Glenlee Lugarno".
In the past 12 months, the median home price in Lugarno has fallen 9 percent - with the average purchase price of a home at $1.56 million, according to PropTrack.