Blue Lake

Blue Lake is a small in Nelson Lakes National Park, in the northern reaches New Zealand's Southern Alps. Sacred to local Maori, it has the clearest natural fresh water in the world. It holds the title of the world's clearest lake. Considered almost as "optically clear" as distilled water.

Use of the lake is highly restricted with bathing, swimming and diving prohibited. Characterized by blue-violet hues seen only in the very clearest natural water. Conservation Department allowed the use of a helicopter to fly in specialist equipment and an inflatable boat.

 The water comes from Lake Constance via an underground river and emerges from springs about 35m above the Blue Lake. The number of visitors to the Blue Lake has been gradually increasing since 2011, the year Niwa's Research was made.

The lake is the two-way hike from the park's entrance. The park is a popular hiking, fishing and destination.