Lake Mashu is located in Akan Mashu National Park, and it is called “Kamuito (God’s Lake)”in the Ainu language since it is considered a mystical lake. The lake surface, where the blue of the sky is reflected in the highly transparent lake water, is called “Mashu Blue,” and its beauty fascinates people for a long time.
Before Lake Mashu was formed, there was Mashu Volcano about 10,000 years ago. It erupted in a large scale about 7,000 years ago, and then Mashu Caldera was formed. The caldera stored rain, fog and snow for thousands years, Lake Mashu finally has been formed as it is today.
Lake Mashu is also called “Foggy Lake”. The lake is often covered by fog especially in summer. It appears and disappears by weather condition, so it is not easy to catch a sight of Lake Mashu under clear blue sky. This might be another reason why it is called a mystical lake.
