When visiting Hokkaido in Japan, there are some places you should not miss. This space will be updated with suggerences and our own experiences.
The Ainu, called it the Devil's Lake, Lake Mashu, or Mashūko (摩 周 湖) as they say in Japanese, is an accumulation of water in the caldera of an extinct volcano in Hokkaido, the northernmost and less inhabited island of Japan. It is exactly the point where the map below shows, at an hour's drive south of Shiretoko. The lake is included in the Akan National Park, and it is place you must see.
Lake Mashu is one of the lakes with the most transparent water in the world, only behind Baikal Lake, though some people say it is not so and that this is indeed the most transparent lake in the world ...
This lake has a depth of more than 40 meters of 'transparency', which is measured by inserting a meter in the water ... which is visible up to 40 meters below the surface. Amazing, is not it?
The caldera of the volcano, was formed relatively recently, only about 7,000 years (in geological terms, very little). In the center of the lake there is a small island (Kamuishu) made mainly of solidified lava after the last eruption.
It is relatively difficult to see the lake because it is almost always quite foggy (is an elevated place) and also you will not be able to be close to the lake ... it can only be seen from viewpoints at the edges. Tourists use to buy mineral water from this place, so if you want you can test the some bottled water. Around the lake there is no construction (as it is usual in Hokkaido).
In short, a recommended visit you can not miss if you like the natural beauty, take away the preconceived idea that some have of Japan with buildings and cities. The only downside to visiting this site is that you need a car ... it is impossible to reach by other means of transport. Our recommendation is to hire a car in Hokkaido or to book a tour to the Mashu Lake, and of course do not forget your camera!