Mt. Ruapehu is the North Island's tallest peak, and it's definitely hard to miss while exploring the Tongariro region. Whether you're coming for the ski slopes in winter or just soaking up the dramatic views in the off-season, the mountain is stunning.
If you're visiting in summer and are up for a bit of a challenge, you can even hike to the summit. The trek to the top is not for the faint of heart, it's an unmarked trail, so definitely consider doing it with a group if you're planning on it. Along the way, you'll pass through some wild volcanic terrain with epic views of Crater Lake. It's always a cool experience, especially when the lake's filled up after eruptions. If you're into hiking and you're in the area, it's totally worth it, but only attempt it if you're prepared and experienced.