Lake Tazawa, a crater lake situated almost in the centre of the eastern part of Akita Prefecture, and at 423.4 meters in depth, is the deepest lake in Japan.
The almost perfectly circular lake is filled with mysterious sapphire-blue water.
Depending on the season and on the depth of light penetrating into the water, the colour changes from jade green to indigo blue, a sure attraction for visitors any time of year.
Take a scenic bus trip around the lake and enjoy views of the lake from different angles.
You can get out on the lake itself, with several options for cruises, plus a range of row-boats and pedal-boats for those who would like to do things under their own stream.
The lakeside is dotted with hotels and rest houses.
In summer, the lake attracts swimmers and sunbathers to its beach area.
It is filled with people who enjoy water sports, such as sail boarding and jet skiing.
In the vicinity are many other leisure spots, including a ski resort and a camping site.