Blue Lake is a volcanic lake that is on the crater of an extinct volcano, the lake is 72 meters deep, the deepest 75 meters, the bottom is flat. The crater is 1200 meters and 824 meters long and the lake is 1087 meters and 657 meters wide. The magic of the blue lake is that from December to March, the lake will appear vibrant blue; after April, it will gradually turn back to cold iron gray until the next December. We were lucky to see its most beautiful look, lamenting that the blue lake is simply a sapphire blue lake embedded in the earth