Despite the North Island's reputation as being far more populated than the wilderness of the South Island, you wouldn't know it upon stepping into Urewera National Park. The largest park on the North Island, located east of popular destinations like Rotorua and Taupo and about a four-and-a-half hour drive southeast of Auckland, Urewera is particularly notable for its forests and lakes and may very well be the most off-the-beaten-path destination on the North Island.
Accessed from the north by the Matahi Valley Road, Urewera is as isolated as you can get, meaning that not only can you tramp through untouched New Zealand forest, but you can do it without a bevy of cruise-shippers in sun visors resting on the trails. The park's two main highlights are its lakes, Lake Waikaremoana and Lake Waikareit. Waikaremoana is the larger of the two and is the beneficiary of one of the country's “great walks,” which takes up to four days and traverses some of the greatest views of the lakes and surrounding landscape. There are plenty of fishing and swimming opportunities as you circumnavigate both lakes, while a few rugged spots along the way make this a trek for true adventurers with moderate conditioning. Be sure to book "great walk" accommodations on the park website if you plan on staying in a hut overnight.
There are also some beautiful waterfalls within this large area; Korokoro Falls can be accessed on the western part of Waikaremoana via a long hike or via boat and a much shorter hike, while Aniwaniwa Falls and Bridal Veil Falls are much more easily reached from the Visitors Center on Lake Waikaremoana. Just be aware that even traveling to the lakes will more than likely need 4-wheel drive due to winding, unpaved roads and may take longer than expected depending on where you are arriving from. It may not be a bad idea to take a guided tour.