Complex sentence: The mountain is in the Aoraki/Mount Cook National Park, in the Canterbury region, which was established in 1953 and along with Westland National Park, Mount Aspiring National Park and Fiordland National Park forms one of the UNESCO World Heritage Sites.
Split into simpler sentences: The mountain is in the Aoraki/Mount Cook National Park, in the Canterbury region. The park was established in 1953 and along with Westland National Park, Mount Aspiring National Park and Fiordland National Park forms one of the UNESCO World Heritage Sites.