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.
If you can see the whole of Lake Mashu, you should seriously go buy a lottery ticket.
This lake is ridiculously clean—so clean you’ll start wondering if someone’s secretly scrubbing it when no one’s looking.

