Blue Lake, also known as Rotomairewhenua, is one of the numerous New Zealand's natural wonders as it contains world's clearest natural waters. It is located within the Nelson Lakes National Park conservation area in the northern parts of South Island. The lake is absolutely transparent, you may see 80 meters deep if you fly by helicopter. Besides the lake is unique due to the blue and violet hues visible only in the purest waters.
Local Maori population treat this lake as a sacred place and believe that humans are not allowed to enter such an unspoilt piece of nature. Since water temperatures are too low ranging from 5 to 8 °C, it is impossible anyway. Recently the absolute clarity of these waters has been proven by the research conducted by NIWA (New Zealand's National Institute of Water). It proves that Blue Lake definitely boasts the clearest waters found in natural basins.
The best time to view this wonder of nature is late spring, summer and autumn. Winter and early spring should be avoided as then you may find icy rind stretched over the lake.