Waitomo Caves, Waikato

Wai means water, tomo means hole. Put them together and you have the perfect name for a region that's packed with limestone caves.

Below the hilly green pastures of the Waitomo region is a subterranean limestone landscape of caves, sinkholes and underground rivers. Once, many millions of years ago, this land was beneath the sea. The limestone was formed by the remains of marine animals, then boosted to the surface by tectonic activity. The name Waitomo comes from the Maori words wai (water) and tomo (hole).

The hundreds of caves in this region have been carved out of the limestone by underground streams. Many of the caves have amazing speleotherms created as water seeps through the limestone to drip off the cave ceilings. Stalactites grow down from the ceiling and stalagmites grow up from the cave floor. If they join together they are called columns or pillars and where they spiral around they are called helicti.

Some caves also have stunning glowworm displays. The New Zealand glowworm (Arachnocampa luminosa) is the larval stage of a flying insect. Its bright blue light attracts tiny flying insects into a curtain of sticky threads.

Above ground you can see fascinating layered limestone rock forms. A walkway that begins opposite the Waitomo Museum of Caves leads through farmland where you'll see sculptured rocks and strange fluted outcrops.

There are various ways to see the sights below the ground. You can walk through some of the caves along well formed paths and stairways. Others present you with the challenge of abseiling, followed by a classic caving experience complete with headlamp. You can also crawl, swim and float through caves – an experience known as 'blackwater rafting'.