New Zealanders weren't surprised when in 2011, scientists carried out a series of tests and found Blue Lake ("Rotomairewhenua" in Māori) in the Nelson Lakes National Park to be the clearest lake in the entire world. The scientists at the National Institute of Water and Atmospheric Research found the visibility of the lake to be more than 262-feet in the natural freshwater, meaning the water is considered nearly as "optically clear" as pure distilled water.
Blue Lake is in the northern area of the Southern Alps mountain range of New Zealand, its waters fed by nearby alpine Lake Constance by way of an underground river. This rare shot of the late from underwater gives a sense of its amazing clarity.
The 393-mile Nelson Lakes National Park was formed in 1956 to provide conservancy for native flora and fauna, including New Zealand's national bird, the kiwi.
You can visit Blue Lake by taking part in the Travers-Sabine Circuit track. This route takes two days and weaves through the lush forest, reaching peak heights of 6,561-feet.
The Māori people, New Zealand's indigenous Polynesian tribe, hold Blue Lake and Lake Constance sacred for ceremonies to release the spirits of the dead. Because of this, the lakes are off-limits for water recreation and visitors are not permitted to enter the lake.
Credit: Twisted Sifter