Lake Tazawa

Tazawako (Lake Tazawa) is a freshwater lake in Semboku City with a maximum depth of 423.4 meters. It is the deepest lake in Japan and the 17th deepest in the world. Often nicknamed "Japan’s Lake Baikal," it is a renowned scenic destination selected as one of Japan’s 100 Landscapes. With its deep, crystal-clear water, the lake is said not to freeze over even in midwinter. When people hear Tazawako, many think of Kunimasu, a species once endemic to the lake. Kunimasu was believed extinct after it could no longer be confirmed around 1948, but in 2010 it was discovered surviving far away in Lake Saiko in Yamanashi Prefecture. This rediscovery became widely known when the Emperor at the time referred to it as a "miracle fish." In 2017, the Tazawako Kunimasu Mirai-kan opened on the lakeshore, exhibiting Kunimasu and Himemasu on loan from Yamanashi. Through panels and videos, the museum explains the story from extinction in Lake Tazawa to rediscovery in Lake Saiko, along with historical fishing tools, dugout canoes, lakeside life, environmental changes, and the biology of Kunimasu—making it a fresh tourism highlight. With sightseeing boats, boat rentals, fish feeding, and more, Lake Tazawa offers plenty to enjoy and is a destination you can easily spend all day exploring. Access is convenient: from JR Tazawako Station, take the Ugo Kotsu bus "Tazawako Isshu Line" and get off at Tazawako Lakeside (about 15 minutes).