The largest freshwater lake in New Zealand, the North Island's Lake Taupo is not only a massive body of water often frequented by boaters and fishermen, but an adventure destination for anyone looking for a thrilling time. About three hours south of Auckland, an hour south of adventure-centric Rotorua, and near enough to a handful of the country's best national parks, you could veritably make a stay in the city of Taupo the center of your big New Zealand trip.
There are some definite highlights to be had at the lake, most of them within easy access from the main tourist center of Taupo. You can skydive over the lake with Taupo Tandem Skydiving, who drop you from the sky for a minute of free fall so you can watch the scenic waters rapidly expand on all sides. You can watch the ground bubble with geothermal activity from the safety of boardwalks at Craters of the Moon, while the Huka Falls are a popular tourist attraction nearby that are somewhat underwhelming in light of the tons of truly amazing waterfalls to be found in New Zealand. Both are part of the Wairakei Tourist Park, which also has plenty of opportunities to indulge your adrenaline with mountain biking tracks, a ropes course, and jet boat rides that will perform high-speed tricks and bring you to the bottom of the falls. Then again, there is bungee jumping and swinging over the Waikato River with Taupo Bungy, where they apparently let you touch the water if you're brave (crazy?) enough.
There is also a more relaxed side to Lake Taupo. You may boat out to Mine Bay, where a 10 meter high carving of Maori legend Ngatoroirangi makes for a cool cultural excursion. There are also a number of short walks that are explained here. For even more information on Lake Taupo, browse the included links and start making a little space in your itinerary for the type of fun to be had here.