The Waitomo Glowworm Caves were discovered in 1887 by Māori Chief Tane Tinorau and English surveyor Fred Mace, who poled a raft into the cavern by candlelight. Within a year, the site opened to visitors, its ceiling constellations of Arachnocampa luminosa larvae drawing naturalists and tourists from across the Pacific. By 1906, the New Zealand government had assumed control, later returning management to Tinorau's descendants in 1989 under the Waitomo Caves Act — a landmark co-governance model that balances conservation with Māori stewardship. Today, the Waitomo Glowworm Caves remain the most visited subterranean attraction in New Zealand, anchoring a karst landscape riddled with 300 documented limestone formations. The Cathedral, a vaulted chamber 18 metres high, carries operatic acoustics Dame Kiri Te Kanawa once tested with impromptu arias. Guided tours descend through three tiers — the Banquet Chamber, Pipe Organ formation, and finally the Glowworm Grotto, where silent boat passages glide beneath a ceiling alive with bioluminescent threads. The larvae produce cold light through a luciferin-luciferase reaction, each pinpoint representing a single insect radiating hunger signals to airborne prey. The effect, magnified by 30 million years of calcium carbonate polishing, resembles a planetarium in reverse. Waitomo caves tour tickets unlock not only the glowworm grottos but adjacent formations: Ruakuri Cave's spiral entrance, engineered to respect Māori burial sites; Aranui Cave's delicate strawwork and fluted columns; and private farm adventures where blackwater rafting threads through underground rivers. The Department of Conservation limits daily visitor numbers to preserve air quality and larval density, a constraint that makes advance booking essential during the southern hemisphere summer. Each tour lasts 45 minutes, timed to align with the larvae's diurnal feeding cycle when bioluminescence peaks between morning and late afternoon.