In a country brimming with adventure, visitors to New Zealand are faced with choosing from a myriad of adrenaline-pumping activities. The country that invented bungee jumping is the same place that offers jet boating, zorbing and fly-by-wire. Though skydiving and river rafting provide thrilling rides, it was a trip to Waitomo Caves that will always linger in my memory.

Creation of the caves began thirty million years ago when the Waitomo region was below sea level. As limestone was lifted out of the sea by geologic activity, rainwater began to flow down the cracks and joints. The acidic water that was created helped to dissolve the limestone and form shafts. Eventually streams flowed through these shafts and created caves that have hosted millions of visitors.

Three caves are open to the public and a wide variety of guide services can accommodate all age groups and abilities. My friend and I joined the 5-hour Black Abyss trip with The Legendary Black Water Rafting Co. along with six other travelers. Our two guides helped us to choose wetsuits, helmets and headlamps. Temperatures in the caves average 16 degrees Celsius and the gear would help us to stay comfortable underground. Though everyone looked a bit silly, we were properly suited to begin cave exploration.

From a platform that hovered above the entrance each person descended into Ruakuri cave. Our harnesses were connected to a cable that dropped into a vertical tunnel of fluorescent ferns and grasses. Squeezing my body through the narrow hole, I found myself descending another 100 feet into a wondrous cathedral of stone. I reached the bottom of the abseil with no problem, unhooked my harness and followed the group through a limestone subway.

Our headlamps provided a strong, steady beam of light that illuminated the walls and iron walkway. The guide instructed us to extinguish our lights and hundreds of feet below the Earth’s surface we found ourselves engulfed by total darkness. The guide strapped my harness to a cable and I went hurdling into the void. As I soared down the zip line, my senses were overwhelmed by the sound of a subterranean river echoing against the grotto walls. A rush of cool air blasted my face as I sped downwards surrounded by the flicker of green Christmas lights. The thousands of tiny emerald stars were in fact glowworms that thrive in Waitomo Caves. The vibrant glow of the larvae appeared eerie and mystical like it belonged in a science fiction movie.

Standing below the starry expanse, we used our headlamps to further explore the details of the cave. The stream that flowed below meandered its way through an ancient labyrinth of limestone caves and grottos. Though the roof was over a hundred feet above our heads, the cave was made up of twisted and turning rock that constantly altered the size of the cave around us.

Our guides presented inflatable tubes and instructed us to make the ten-foot jump into the river. Floating in my tube adjusting to the coolness, I stared dreamily at walls bejeweled by thousands of glowworms. The New Zealand glowworm is a two-winged insect at the ‘larva’ stage of its life cycle that emits light to attract food. There were so many of the tiny glowing lights that the walls appeared as neon billboards.