The Waitomo Glowworm Cave is located in the Waikato region of New Zealand's North Island. It is part of the Waitomo Caves system, which includes Ruakuri Cave and Aranui Cave. As the name suggests, the cave serves as the home to glowworms, specifically Arachnocampa luminosa, which are a type of fungus gnat species that glow in their larval stage. Because it was underwater 30 million years ago, the cave is made from limestone composed of fossilized shells, skeletons and coral.