The focus of the Nelson Lakes National Park are Lakes Rotoiti and Rotoroa. It is also home to the northernmost peaks of the Southern Alps, and many travellers come here for the superb hiking and walking trails around Mount Robert.
St Arnaud is a small alpine village with a laid-back atmosphere and a couple of good hostels. There is a kiwi sanctuary here, so it is a good place to come if you want to spot these endangered birds. There are also kayaking tours, as well as rafting trips on the river.
The scenery in the surrounding valleys, mountains and hills is excellent.