A reflection rotated 180 degrees.
I’ve never succeeded in getting an adequate photo of this remarkable geological phenomenon, which is set amidst upland rainforest at Mt Hypipamee.
But on this recent visit, the water was unusually clear … this is an inverted reflection; see the next image for the original photo.

The Crater is a diatreme – the result of hot lava hitting a gas pocket underground, generating an explosion that in this case has torn an almighty hole through solid granite.
The Crater is 70 m across and 128 m deep (of which 70 m is filled with water).
As there’s no remnant volcanic material, it hasn’t been possible to determine when this explosion occurred.