Lake Mashu

Situated in the eastern part of Hokkaido, u is a caldera lake located within the "Akan-Mashu National Park". Encompassing an area of about 19.6 km² with a circumference of roughly 20 km, the environs of the vast lake have been designated as a special protection area. Due to the steep cliffs surrounding it, direct access to the lake is restricted. However, several observation decks set up around the lake offer panoramic views of its serene surface.

In the Ainu language, Lake Mashu is referred to as "Kamuito", which translates to "God's Lake". The water of the lake, known for its unparalleled clarity worldwide, reflects the blue sky, resulting in a unique, deep hue known as "Mashu Blue". The lake's appearance varies moment by moment, influenced by the movements of clouds and the sun. On windless days, its enchanting blue shade becomes even more prominent.

There are three observation decks around the lake, each offering different perspectives of Lake Mashu. The most accessible and popular among them is the "First Observation Deck of Lake Mashu". In 2022, the rest house was revamped as "Lake Mashu Kamuy Terrace", from which visitors can enjoy a breathtaking view. From the "Third Observation Deck of Lake Mashu", visitors can get a close view of Kamuishu Island, offering a dynamic panorama. The "Rear Mashu Observation Deck" is less frequented, allowing visitors a tranquil experience of standing face-to-face with the lake.