Buchan Caves and a railway bridge and Lonesome bay - Page 1

This is a close up of some calcification. Again it looks like coral. But actually, it might be? This used to be ocean, like much of Australia.
Camera Details: SONY, ILCE-7M2
Settings: 4/10 at f/2.5, ISO 1600, 28 mm
Date: 24 December 2018 Time: 10:43:29