Of New Zealand's 20 peaks over 3,000 metres, all except Mount Aspiring / Tititea lie in the park. These include New Zealand's highest mountain, Aoraki / Mount Cook, at 3,724 metres. Other prominent peaks include Mt Tasman, Mt Hicks, Mt Sefton and Mt Elie de Beaumont. The mountains of the Southern Alps in general are young, less than ten million years old, and are still building. Uplift in the region of the national park is at the rate of 5–10 mm per year. It's estimated that approximately 25 km of uplift has occurred, however the rate of uplift has been countered by erosion.