This 30-million-year-old cave in New Zealand has a beautiful phenomenon that doesn't exist anywhere else in the world

Deep underground in New Zealand's North Island, a winding underground universe of limestone caves glow with a magical blue-green light. While it might seem like pure fantasy, these caves are very real. Their dark interior is brought to life by twinkling colonies of glow worms, or arachnocampa luminosa.

Auckland photographer Joseph Michael documented the sparkling caves by spending countless hours in the frigid underworld of the caves, which experts estimate dates back some 30 million years.