Waitomo Glowworm Caves, New Zealand

The Waitomo Glowworm Caves, located in the southern Waikato region of the North Island of New Zealand, is a famous attraction because of glowworms or Arachnocampa luminosa. They are around the size of an average mosquito, bioluminescent creatures that produce a blue-green light and are found exclusively in New Zealand. 

The Waitomo Glowworm Caves were first explored in 1887 by local Maori Chief Tane Tinorau accompanied by an English surveyor Fred Mace. Local Maori people knew of the Caves existence, but the subterranean caverns had never been extensively explored until Fred and Tane went to investigate. The limestone formations in the Waitomo Glowworm Caves were formed when the region was still under the ocean about 30 million years ago.

Source : en.wikipedia.org