Emerald Lakes growing on the surface
On the edge of one of the 3 Emerald Lakes near the summit of the Tongariro Alpine crossing. The Emerald Lakes’ brilliant colour is caused by minerals leaching from the adjoining thermal area. You can see thermal steaming around the Red Crater and Emerald Lakes. These vents are also responsible for the sulphurous smell.
The Maori name for the lakes is Ngarotopounamu meaning greenstone-hued lakes. The water is cold and acidic and is not suitable for swimming or drinking. The lake freezes in winter.