In 1960, drillers prospecting a new part of the Wairākei field got more than they bargained for when steam forced its way up the outside of the bore casing and exploded at the surface. It sent up a plume of steam visible 120 kilometres away, and created a crater 22 metres deep and 70 metres long. Crews tried to seal the hole by pouring in vast quantities of thick mud and cement, but water continued to erupt and the crater got bigger. Over several months it swallowed up the original drilling platform, part of the access road and some of the hillside. Attempts to contain the ‘rogue bore’, as it became known, were eventually abandoned, and it became a tourist attraction. A Rotorua-based journalist, Ross Annabell, dodged a series of locked gates and warning signs to visit it, as he described in Hot water country (1962):

‘Below us was a small steaming lake about 90 m wide, set in a sort of crater about 15 m deep, with earth walls which shook visibly under the continuous impact of some hammer-like subterranean force… in the crater bottom a furious, steaming, boiling lake of dark grey murky water was in violent motion, stirred by almost continuous steam eruptions. The pressures built up every two or three minutes to a furious geyser eruption which hurled a column of dark muddy water nine to 15 metres into the air, with an accompanying column of steam which shot more than 90 m above the hilltop … it was horrifying, yet utterly fascinating. We felt like running, yet our legs remained immobilised by mixed fright and curiosity. It was far more than a tourist spectacle; it was a feel, a pulsating, horrifying feel that reverberated through the very soles of our feet.

‘Overseas visitors who saw the bore declared it was the highlight of their visit to New Zealand.’

The rogue bore died down of its own accord in 1975, and the photograph shows the crater left behind. The person at upper right gives a sense of scale.