There are numerous limestone caves in the South Auckland District, the best known being the Waitomo, Raukuri, and Aranui Caves. These have been developed as tourist attractions at Waitomo, about 50 miles south of Hamilton. They have their setting in attractive surroundings of bizarre limestone outcrops, patches of bush, and streams and fields. Guides from the nearby hostel lead visitors along paths which are lit both for safety and for easy inspection of the limestone formations. The boat journey along the underground river to the Glow-worm Grotto, which is lit by the countless, tiny, clear lights of glow worms, is one of the many unique attractions of the caves.
The caves are channels that have been dissolved out of limestone by underground streams over many thousands of years. Water seeping down through the limestone becomes fully charged with lime in solution. As this drips from the cavern roofs some of the water evaporates leaving a minute deposit of lime behind. Thus, with time, all the caves have become elaborated by stalactites, stalagmites, and incrustations. Many of these, namely, the Bride's Jewels, the Organ, the White Terrace, the Blanket Chamber, etc., are of intricate design and beautiful form.
The name Waitomo means “water entering a hole” or, more aptly, “water passing through a hole”.
by James Cecil Schofield, M.SC., New Zealand Geological Survey, Otahuhu.