Black Water Rafting and Fluorescent Worm Larvae

One of the most varied and fascinating places to head underground must surely be Waitomo Caves. This natural cave system, 200km (125miles) South of Auckland on the North island, consists of 3 different subterranean experiences; The Glow-worm Caves, Ruakuri Caves and Aranui Caves.

The glow worm caves, are a series of underground caverns which carry an underground stream with thousands of luminous, glowing worms hanging from the roof. You can take a ride down the stream with a guide to learn a bit more about the unusual worm, Arachnocampa luminosa, known to the Maoris as Titwai. It's the larval stage of the insect which glows in order to attract prey into sticky threads of silk it dangles below itself to trap prey before hauling it up.

With its stunningly-architected spiral stair down to the cave entrance, you know you are in for something  special as you descend into Ruakari. The caves were first discovered almost half a millennium ago by a wandering Maori hunter when he was attacked by dogs who were using the mouth of the caves for refuge. Although you can travel the winding 1.6 km (1 mile) system on foot across heady walkways, Ruakari is where the infamous black water rafting takes place. Not as scary as it sounds, the caves have an excellent safety record for their trips where you ride what looks like a truck inner tube down the cave river in a wetsuit and helmet. Some of the access is not for the faint-hearted though as it involves a high abseil and a squeeze through some rocks to the rafting point.

For the perhaps less adventurous and more geologically-minded, the smaller and drier Aranui caves offer a spectacle of rock formations including stalactites, wetas and flowstones formed in delicate brown, pink and white limestone. Named after the local Maori man who discovered the cave system, Aranui is a place sacred to the Maori and with an air of magic about it. Aranui is situated close to the Glow worm caves if you want to experience both and is suitable for all ages as long as you're not bothered by the large crickets which live in crevices near the entrance...