Great photograph. i assume that the sandstone blocks and gravel are part of landscaping? These uncommon goannas like to shelter in deep cavities under piles of very large rocks like these. They will also shelter in hollow logs and burrows.
Thanks for the feedback. The Rosenberg's have been coming since 2013 and we re-landscaped with all the gravel etc. in 2016. We also have lots of fallen timber, logs and other reptile friendly habitat both near the house and throughout the property. We have a huge boulder retaining wall near the house that we have seen one go into... fingers crossed that one or two decide to shelter on a regular basis. :)