Michael,
As far as undeveloped the land, probably the most famous great piece of land I've seen is the Inch Peninsula in Dingle Bay right across from Dooks, one of my favorite places in golf.
There are some big time developers who are well aware of the property, e.g., Herb Kohler, but getting planning permission has been damn near impossible.
Dr. Arthur Spring, whose brother was once prime minister, is the person who introduced me to the property. At the point (circa 2000), he had already spent about fifteen years trying to get permits. So, it just may never happen.
But, the place is amazing. There are golf holes all over the place. The only problem is what some have called "embryonic dunes" that you might not actually be able to build on.
The other place worth mentioning is the Mornington Peninsula south of Melbourne. Of course, there are several golf courses down there, including my favorite of Tom Doak's course - St Andrews Beach. But, my impression is that more good to great land exists there that would be great for golf.