Lake Shikotsu is a caldera lake formed by an eruption of Shikotsu Volcano about 40,000 years ago. The transparency is extremely high and the water quality has been rated the best in Japan for 11 consecutive years until 2018! You can feel how clear the water is when you go out to the lake by clear bottom Kayak. Today, it was little too windy to go out to the lake by kayak so we went out to Chitose River where is just outflow of Lake Shikotsu. Just beautiful..