Melissani Cave, on Kefalonia Island in Greece, features a sky-blue lake within the cave. The lake is shallow and clear, and is covered with stones at the bottom. The cave was rediscovered in (In Greek mythology, Melissani was the cave of the nymphs.
Marble Cave, Chile Chico, Chile & The most spectacular caves network in the world and this Marble Cathedral is absolutely magnificent. It& located in Patagonia, Chile on the second largest freshwater lake in South America, General Carrera.