Drakolimni (Greek: Δρακολίμνη, Dragon lake) is the name of several alpine or sub-alpine lakes in northwestern Greece Epirus periphery: the ones in mountain Tymfi and Smolikas are the most widely known. According to local folktales the lakes used to be inhabited by dragons who fought each other by throwing pines and rocks and thus created the peculiar landscape and gave their names to the lakes 

http://en.wikipedia.org/wiki/Drakolimni