Kings and Caves03 April 2017
When you look out over the landscape, it's hard to believe that some 28,000 years ago Auckland's largest explosion produced a crater 800 metres across and at least 200 metres deep. It spewed out enough rock and volcanic ash to create a layer one metre thick, over four kilometres away. A strong south-westerly wind was blowing that day, and ash built up on the north-eastern side of the vents, with some scattering and covering parts of One Tree Hill in layers up to three metres thick.
After the initial eruption, the crater filled with lava and the landscape we know as Three Kings was formed. Some lava overflowed, and ran down through the valley and into the Waitemata Harbour. As it ran, the outside layers cooled faster and solidified, and caves and tunnels were created where the hot lava flowed out.
Today, thanks to mining, Big King - the second highest peak - is all that remains of the cones, and the Big King Reserve, which covers its flanks, is a favourite place to go for a walk. The reserve offers a mix of level walking and steep slopes to explore, and requires sturdy shoes and a moderate level of fitness. If you walk to the top you will gain outstanding views of the Manukau and Waitemata Harbours, the Waitakere Ranges, and a wide cityscape.
To see layers of ash produced by the volcano, take a stroll down nearby Liverpool Street (reached via Buckley Road). Here, the sedimentary layers can be seen in the banks lining the road. If you look closely, you'll even be able to see where earthquakes have shaken Auckland in the past, jolting the sedimentary layers into an almost zigzag like pattern.
Today many of the caves formed in the Kings lava flow have collapsed or been filled in, but even so there are still 17 known caves including Stewart's Cave, a large cavern which lies beneath several private residential properties. It was named after James Stewart, an engineer who proved that parts of Auckland's lava beds were cavernous, and subsequently surveyed the area.
More accessible, with wooden stairs and a hand rail, is the cave found in Annie and Sean Jacob's backyard on Landscape Road. Thousands of people, including one 93-year-old, have assessed the cave thanks to the couple opening their garden to the Mercy Hospice Heroic Gardens tours. For further information on upcoming tours visit www.heroicgardens.org.nz.