Nelson Lakes National Park is located in the northern half of New Zealand's South Island. Its eastern and southeastern territories lie on the borderland between its home state Tasman and the regions of Marlborough, Canterbury and Westland. The park was established in 1956 and covers an area of 101,800 ha that is highlighted by two large alpine lakes: Lake Rotoiti and Lake Rotoroa. Several smaller freshwater bodies and streams are distributed throughout the park.
Nelson Lakes National Park surrounds the northernmost snow-capped mountain range of the Southern Alps, Spenser Mountains. Emily Peaks lies parallel to the border between Tasman and Westland along a freshwater stream named Glenroy that feeds the Matakitaki River further north. The Matakitaki River rises from the valley between Emily Peaks and Ella Range. From here, it is an interplay between mountainous range and beech covered valley that leads north to the lakes of Rotoroa and Rotoiti. The lakes are separated by the Travers Range around Mount Hopeless. Centre of the entire Spenser Mountains is Mount Franklyn which peaks at about 2340 m.
Lake Rotoiti and Lake Rotoroa, as many other bodies of water in New Zealand, are remnants of the country's last ice age. Fresh water from natural springs and melting snow caps provides a habitat for a diverse number of plant and bird species. Maori legends attribute the creation of Nelson Lakes to Rakaihautu, who is said to had dug out two huge holes, and had filled them with food for his companions. Today, the lakes are the park's main attraction.