A flock of starlings flies over Lake Leman on an autumn morning in the Lavaux near Grandvaux, Switzerland October 20, 2016. (Photo by Denis Balibouse/Reuters)
Located in East Java, Indonesia, Kawah Ijen is a volcano is home to the largest acidic crater lake in the world. What turns the waters of the lake in the 1 km caldera its beautiful turquoise color are the highly sulfuric gases emitted from the volcano underneath.
Located at the foot of the Rocky Mountains on the North Saskatchewan River, the rare phenomenon occurs each winter in the man-made lake. Photo: Ice bubbles in Abraham Lake. (Photo by Chip Phillips/Rex Features)