To view an informative map showing the Commonwealth War Graves WW1 Cemeteries in the Somme region of France, go to:
http://www.greatwar.co.uk/places/somme-cemeteries.htm
To view an informative map showing the Commonwealth War Graves WW1 Cemeteries in most of Belgium, go to:
http://www.greatwar.co.uk/places/ypres-salient-cemeteries.htm
To find more details, including a map location of cemeteries not included in the above, go to:
https://www.cwgc.org/find/find-cemeteries-and-memorials
Enter the name of the Country, the name of the cemetery, tick WW1 and search.
For an additional perspective on Australian involvement in WW1 and details of the number of Australians who have no known grave, go to:
https://www.cwgc.org/history-and-archives/first-world-war/forces/australia