We saw this odd tree in a pasture alongside the road in Eden Valley. It was so odd that I turned the car around so we could take a photo of it.
Then we saw an even bigger tree with the same odd look. And another. And another. And a hundred others along the same highway.
Coincidentally, one of the friends we were meeting for lunch used to run Forestry South Australia, so we asked him what causes this strange, hollow, burned-out look.
Two possible causes, he said. The first is bush fires. And if the trees are old enough aborigines may have used fire to hollow them out intentionally for use as permanent homes or as temporary protection from the elements.