Ruakuri Cave in Waitomo, New Zealand has a mesmerizing blue glow that is a sight to behold, but the beautiful light comes from an unexpected source: glow worms. The glow worms hang from the cave ...

It takes just minutes for the earth to swallow me whole as I abseil into the cave’s mouth. My feet bounce off rock until suddenly the wall slopes away into a yawning cavern and I’m kicking out at open ...