The most popular tourist attraction in New Zealand is the Waitomo caves.  You can explore them via a tour-guided boat, or you can encase yourself in a wetsuit, snag an inner tube, and get a more visceral experience.  Tuan and I chose the second option.

At times it’s so tight that you can barely squeeze inbetween the rocks. At several points, you cascade over a tiny slide/waterfall, barreling down into blackness and splashing into the cold water at the bottom.  At other times, your tour guide (barely old enough to shave) leads you in a rousing chorus of “I’m a Little Glow Worm”:

I’m a little glow worm
Short and stout
Life is not very glum
Because light shines out my bum.

Because the Waitomo Caves are some of the only caves on the planet where glow worms secrete on the rocky ceilings, which results in an amazing visual effect.  Despite the splashing and the tubing and the singing, the best part of the caves is when you float along quietly in the dark, your neck craned upwards--where, somehow, worm shit has created dazzling, iridescent galaxies.  Stunning graffiti.  Angel’s facepaint.