Some 16km southwest of Otorohanga (8km west of SH3), WAITOMO is a diminutive village of under fifty inhabitants with an outsize reputation for incredible cave trips and magnificent karst features – streams that disappear down funnel-shaped sinkholes (Waitomo means “water entering shaft” in Maori), craggy limestone outcrops, fluted rocks, potholes and natural bridges caused by cave ceiling collapses. Below ground, seeping water has sculpted the rock into eerie and extraordinary shapes. The ongoing process of cave creation involves the interaction of rainwater and carbon dioxide from the air, which together form a weak acid. As more carbon dioxide is absorbed from the soil the acid grows stronger, dissolving the limestone and enlarging cracks and joints, eventually forming the varied caves you see today. Each year a further seventy cubic metres of limestone (about the size of a double-decker bus) is dissolved. Many of the caves are dazzlingly illuminated by glowworms.
The bulk of the caves are in (or visited from) Waitomo: for DIY limestone scenery sightseeing in any weather, head west to Mangapohue Natural Bridge and Piripiri Caves.
Local chief Tane Tinorau introduced Waitomo’s underground passages to English surveyor Fred Mace, in 1887. The pair explored further, building a raft of flax stems and drifting along an underground stream, with candles their only source of light. Within a year, the enterprising Tane was guiding tourists to see the spectacle. The government took over in 1906 and it wasn’t until 1989 that the caves were returned to their Maori owners, who receive a percentage of all revenue generated and participate in the site’s management.