Located at the foot of the Hochschwab mountains in Austria, the Grüner See is a county park during the frosty winter season. However, after the temperatures start to go up in spring, and the ice and snow starts to melt, the park floods with crystal clear water. The water ranges from around a couple of meters deep during the winter season up to 10 meters during the summer time, when it turns into a paradise for divers and tourists. The waters slowly begin to recede by the end of July. Can’t tell you how badly I want to see this before I die!