Kiama blowhole was first observed by a european in 1797 by George Bass.
Bass described it in these words:
"The earth for a considerable distance round in the form approaching a circle seemed to have given way; it was now a green slope ... Towards the centre was a deep ragged hole of about 25 to 30 feet in diameter and on one side of it the sea washed in through a subterranean passage . . . with a most tremendous noise”.