Australian ballet dancers rehearse their moves on Whitehaven Beach on June 11, 2010 on Hamilton Island, Australia. (Photo by James Morgan/Hamilton Island via Getty Images)
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.