It is in Victoria, Australia.
The boundaries are not rigid but basically cover an arc from the Otways up to a little south of Ballarat, across to Werribee and all points to the south east of that area.
The region is rich in history and played a major part in the early history of Victoria.
There are numerous local and family history societies and museums that are a wonderful resource for anyone researching in our region.
The Geelong & District web site will help you with that research.