A volcanic eruption in Northern Queensland more than 199,000 years ago spewed lava streams 23 kilometres long creating the Undara lava tubes. A remarkable refuge for wildlife, researchers are drawn to the tubes to discover why the population of cave creatures is so high; to examine the similarity of its basalt to that on the Moon; and to observe the changes that the seasons bring to the lives of the bats, beetles, spiders, mites, flies and moths that inhabit them.