Gosaikunda in Nepal's Langtang National Park is an alpine freshwater lake located at an elevation of 4,380m and a religious site for the Hindus. A World Heritage Site, the amazing blue of the Gosaikunda Lakes is a reflection of the sky. It changes color depending on the sky and also shadows of the mountains falling on them. In this photo, part of the lake is blue where the sky is reflected directly on it while the other side is turquoise where the mountain above it cast a soft shadow on it.