Fukushima Lake Inawashiro - The Sky Mirror Lake
Lake Inawashiro in Fukushima Prefecture is Japan's fourth largest lake with a surface area of 103.3 km². The lake formed over 30,000 years ago as a result of Mt. Bandai's eruption causing a tectonic depression to be dammed. Lake Inawashiro's water is very acidic with a pH of about 5.0, while a pH of 7.0 is considered neutral. The lake's water is also known for being extremely transparent, earning its nickname "Heavenly Mirror Lake". The water is so clear that Mt. Bandai's reflection on the lake can be seen on its surface.