in New Zealand’s South Island, lies a magical blue-violet lake. Surrounded by steep alpine forests and spring-fed from the glacial waters of Lake Constance, it is small but not insignificant.

Hidden deep in New Zealand’s wilderness ... s exceptional purity is thanks to underground seepage from nearby Lake Constance, which filters out nearly all particles before they enter Blue ...

Tourists visiting New Zealand’s Nelson Lakes National Park ... The small alpine lake, fed by the glacial waters of Lake Constance, is a sacred site. It was first discovered by the Maori iwi ...

In New Zealand’s Nelson Lakes National Park, about 1,200 meters (4,000 feet) above sea level and a two-day hike from nearest civilization, lies Rotomairewhenua, or Blue Lake. (CNN/Janet Newel) ...