Moruya was a source of very high quality granite, with several quarries alongside the Moruya River. Most people would recognise the Sydney Harbour Bridge - the granite for the towers at the ends of the arch came from Moruya. It was taken up the coast on barges, and this wreck is (as far as I'm aware) the only surviving remains of one of those barges. Second image in PiP.

Explored.