From the World Heritage inscription:
In 1993 Tongariro became the first property to be inscribed on the World Heritage List under the revised criteria describing cultural landscapes. The mountains at the heart of the park have cultural and religious significance for the Maori people and symbolize the spiritual links between this community and its environment. The park has active and extinct volcanoes, a diverse range of ecosystems and some spectacular landscapes.
You have probably seen images from Tongariro National Park before without knowing it. Mt. Ngaruhoe which is inside the park was made famous as the fictional Mt. Doom in the Lord of the Rings movies. It is a popular location for skiing and treking in New Zealand and is one of the highlight of the North Island. It is a day’s drive from Auckland and should be on your list of places to visit if you ever find yourself on the North Island.
View my complete list of UNESCO World Heritage sites.