Spelunking — also known as caving or potholing — is the thrilling sport of exploring wild cave systems. It might involve lots of climbing, rappelling and crawling depending on how big the space is.

In New Zealand, there are plenteous undiscovered underground systems that can make spelunking fanatics go wild. From cave tubing to swimming in an underground waterfall — the Ruakuri Cave and Waitomo Caves are some of the best in the country to explore.