I have only been studying this for about two years, but in this time I was able to easily put two and two together and see what is going on. The question is, why have others not been able to do the same? It is pretty clear there were no protection mechanisms at all in Western Victoria in the 19th century and farmers were able to destroy what they wanted. I believe they may have feared the return of the aboriginees and wished to obliterate all remaining traces. The current remaining stonehenges are located in semi-secret locations, one protected by Park Rangers, thank goodness. As late as the 1940s, a remarkable Avebury-like stone serpent was in fact obliterated in New South Wales.
I feel this is very similar to the pre-Maori civilization of New Zealand, which people have described as 'Celtic'. I would in fact describe it as partly 'Toltec' or even 'Terascan.' These people were a mixture of Atlantics and Native Americans, as certain of their artefacts appear 'Celtic.' in appearance. It all goes to show there were MANY world-explorers, long long long before Colombus!"