Hiking & Walking: The eastern coast of the North Island has several excellent bushwalking trails, including the Tongariro Crossing, which brings you through the alpine areas in Tongariro National Park. Some of the most rugged bush in the country is in Te Urewera National Park southeast of Rotorua, and hikes abound around Rotorua and Taupo. Just don't tackle the mountain terrain unprepared—the weather changes rapidly.
Maori Ceremonial Feast: Rotorua may be the best place in New Zealand to try the Maori feast known as a hangi. Traditionally, the meal is made by lining a hangi pit, or earth oven, with heated stones and wet leaves, and then filling it with lamb, pork, chicken, seafood, potatoes, pumpkin, and kumara (sweet potato). Nowadays, the food may be prepared aboveground, but when it's done well, it doesn't lose much in the translation.
Soaking: In Rotorua and Taupo, thermal springs are on tap. You can soak in your own thermal bath in even the cheapest hotels in Rotorua or take advantage of public facilities such as Polynesian Spa. Many Taupo hotels also have their own thermal baths or pools. Lie back and close your eyes.
World-Class Fishing: Central North Island is trout country. You can get out on any of the designated lakes and waterways if you have your own gear and a fishing license—but a local guide can take you to the right spots. Anglers rarely leave Lake Taupo, the lakes around Rotorua, or the rivers farther south around Turangi disappointed.