Accoladed scientist and author Jared Diamond has said that the closest human beings have come to visiting an alien planet was when Moananui explorers first landed their waka on the shores of Aotearoa. If our ecosystems are unique enough to warrant comparison with extra-terrestrial life, then life in our remote caves must be even more alien. BioHeritage spoke to Anna Stewart, research and conservation coordinator at The New Zealand Speleology Society, about these lightless worlds and how to protect them.