Kiama was the site of two strong volcanic flows, called the Gerringong Volcanics, which came out of Saddleback Mountain, now a collapsed volcanic vent. The Kiama Blowhole is part of an erosion process on the more recent rock, formed into columnar basalt, or latite. Before the cedar-getters (a rowdy mob of ex-convicts, convicts and runaways, some with cedar licences and many without) had even arrived in the area, around 1810, the local Indigenous Australians Wodi Wodi of the language group Dharawal had been using the land for thousands of years, moving every six weeks or so in family groups. This is supported by a midden of shells at nearby Bass Point used for more than 17,000 years. During this time the whole coastal hills was covered in rainforest and cedar brush. There is evidence of a flourishing culture with intricate possum cloaks, a developed song and story cycle and a deep understanding of the many plants of the rainforest. Only a few remnants of rainforest survive along the escarpment in places like the Minnamurra Rainforest Centre. There is strong evidence of recent sea debris showing a mega-tsunami hit this coast around 1487 A.D according to Dr Ted Bryant of Wollongong University. The first European to explore the area was George Bass who stopped there on his whaleboat voyage to Bass Strait on 6 December 1797. He noted the beauty and complexity of the Kiama area and was astounded when he first discovered the blowhole.
During the colonisation of Australia, the Kiama area was settled by wheat farmers as the soil was volcanic and rain-swept unlike most of Australia. Early Jamberoo was the population centre from about 1830 to the 1860s and when the wheat died, the farmers switched to dairying. During this period Kiama became the best example of 'chain migration' in Australia as many assisted migrants came from Northern Ireland on clearing leases and eventually half the marriages in the Kiama Anglican Church in a hundred years had Northern Irish
