Mountaineers explore upwards, but cavers climb down into the earth to see glow-worm grottoes, underground waterfalls and strange rock formations. They also look for new caves and tunnels. People who study caves (as well as exploring them) are called speleologists.
How do caves form?
Caves are formed as rock is worn away, for instance by rainwater or the sea. Limestone and marble caves are common. Over millions of years, acids in rainwater erode the rock, creating a maze of underground caves, tunnels and streams.
New Zealand caves
New Zealand has hundreds of limestone or marble caves. They are in two main regions:
- The King Country, in the North Island
- North-west Nelson and the West Coast, in the South Island.
Waves have also formed sea caves all around the coast. Auckland’s volcanic cones have tunnels known as lava tubes.
Important caves include:
- Waitomo Caves. These are near Te Kūiti in the King Country, and thousands visit to see the glittering glow-worms there. Tourists also go black-water rafting – floating through a cave on a rubber tube. You can see long rocks growing downwards (stalactites) and upwards (stalagmites).
- Te Ana-au Glow-worm Caves in Fiordland.
- Harwoods Hole near Nelson. The first caver to be lowered into it was a schoolboy, in 1958. At 183 metres his feet touched bottom. It was the country’s deepest known cave at the time.
- Nettlebed Cave. On Mt Arthur, in north-west Nelson, this is New Zealand’s deepest cave at 889 metres.
- Bulmer Cavern. Near Nettlebed, this is the country’s longest cave at over 50 kilometres.
Caving in New Zealand
The most popular area is north-west Nelson. The marble rock within Mt Owen, Mt Arthur and Tākaka hill has many caves, and more are being discovered.
Equipment and safety
A light source is vital: cavers wear headlamps and carry torches. They use a harness when climbing steep rock. Often they can drink from underground streams.
Strict safety rules include carrying three light sources and a map. If you are badly injured while deep underground, rescuers need to carry you out on a stretcher.