PHOTO: No. 233 & 233a Edinburgh Rd, Castlecrag, has been in the same family since 1938. On the market for $6 million, it is one of Sydney’s most private waterfront homes.

THE most secluded property on Sydney Harbour is up for sale for the first time in 80 years.

The modest property sits on a whopping 6500sqm of untouched bushland right on the edge of Sugarloaf Bay in Castlecrag.

The heritage listed three-bedroom house at 233 and 233a Edinburgh Road, Castlecrag, was built in 1912 out of Canadian redwood.

Listed with Ray White Lower North Shore’s Chris Keane, it has a $6 million price guide.