The only place in the world where the water is known to be as clean is under the Ross Ice Shelf in Antactica. This picture shows how the perceived colour of the rock changes with depth. Nearer the edge of the pool the rocks can be seen as yellow or white, much as they appear in the air. As the water gets deeper, colour is refracted away and the same rocks appear as light blue by about 4m depth. Further away, when the pool reaches its maximum of 7m depth, only blue light makes it through and the rocks seem to be dark blue but are still clearly visible. This change is entirely due to the refraction in the clear water, undimmed by minerals or silt.
The springs are also believed to be the home of the taniwha (water monster) Huriawa.