What Lies Beneath

Aotearoa New Zealand was born from massive seismic activity, and an eerily beautiful reminder of what shaped our shaky isles lies right beneath your feet in Tāmaki Makaurau Auckland.

PREDOMINANTLY FOUND AROUND THE CITY’S volcanic hills, but also lurking in backyards and beneath buildings, Auckland’s lava caves are remnants of a time when violent eruptions rocked the land and molten rock flowed through the suburbs of the City of Sails.

Aotearoa New Zealand was born from massive seismic activity, and an eerily beautiful reminder of what shaped our shaky isles lies right beneath your feet in Tāmaki Makaurau Auckland.

Some caves date back hundreds of thousands of years, others were created as recently as around 600 years ago when Rangitoto erupted. All were formed in the same manner. “A lava cave is created as a crust forms on a lava flow,” says Kate Lewis, who together with Christina Bloom make up part of the Auckland Council team tasked with monitoring and preserving the caves.

“The crust solidifies, but the molten lava inside continues to flow, and when the eruption finishes it flows out the other end and leaves this hollow tube or tunnel. Some can be very short - just a few metres - but others can be quite long. The longest we have in Auckland is the Wiri cave, which is around 290 metres long.”

“Part of what our team does is deal with accidental discoveries of lava caves,” Christina says, “which are typically found during earthworks or construction work. When someone is digging a hole in the ground, they may then crack into the roof or into part of a lava cave. Some people are unaware that the caves are protected, but hopefully they contact our team and we document it and work with the person who’s found it to figure out the next steps.”

Those next steps may include sealing the cave for safety reasons and to deter vandals, or developing construction methodologies to reduce vibration, as well as working with geotechnical engineers to re-design structures over and around caves safely. But it is a basic principle that the caves are not filled in and are instead preserved for future generations.

Perhaps the most bizarre use of a cave was during the early years of WW2

This has not always been the case sadly. “Early Europeans tended to use the caves as dumping grounds,” says Kate. “They can often be found filled with household rubbish and empty beer bottles, although they were also used for things like growing mushrooms. For Māori, the caves are sacred as they were often used as burial sites, where the remains of ancestors were laid to rest; sadly many of these remains were stolen over the years. But the caves were also used for storage of things like kūmara and even for getting from A to B.”

Perhaps the most bizarre use of a cave was during the early years of WW2, when New Zealand Communist Party members Sid Scott and Gordon Watson set up a clandestine printing press in the Wiri cave. The Party had been driven - literally - underground because of Moscow’s (soon to be broken) pact with Nazi Germany, and the press was used to produce its broadsheet the People’s Voice, which was then smuggled out of Auckland and distributed around the country. Scott and Watson worked in dark, damp and cramped conditions for months until three schoolboys stumbled on the cave and alerted Police in September 1940; neither of the two men were there at the time and evaded arrest.

Someone else used to working in cold damp lava caves is Chirag Jindal, the founder and director of Arclab, one of New Zealand’s leading surveying companies. Chirag became aware of the work of Peter Crossley, who for decades has been documenting the lava caves, and after meeting him joined in a project to accurately map the caves using terrestrial light detection and ranging (LIDAR). The detailed 3D imagery created by Chirag offers an incredible - and quite beautiful - glimpse into the caves, but also helps to place them not only in our physical landscape but in our mental landscape too.

“I first met Peter about eight years ago,” Chirag says, “and we talked about how some of the caves were being destroyed and the need to record the caves in some way. Given my architectural background my interest was in the relationship between the caves and the built environment.

These datasets are not only for archival purposes and resource consenting, but also about revealing the landscape and bringing it into the public forum. A lot of people don’t know the caves even exist, so this was a way of bringing them into our urban and collective narrative, which means they are much less likely to be dismissed and destroyed.”

“Some caves are surprisingly large, up to seven metres in height” Chirag says, “in others you are on your hands and knees. There is a cave in Māngere the speleologists call ‘The cave of a thousand press ups’ - mapping it was a decent upper body workout!”

The caves are not filled in and are instead preserved for future generations

Chirag’s work has been exhibited in New Zealand and overseas, and will be culminating in a publication of imagery and essays next year. “The book will be about asking the questions of how we relate to them, their pre-colonial past, their future, and what do they mean to us. We’re surrounded by these lush green hills, and that is our understanding of the volcanic landscape; it’s only when you go into the lava caves that you begin to understand the volatility of the landscape.”