Japan’s third-largest lake, Towada-ko (十和田湖), fills a 300m-deep volcanic crater in the northern portion of the Towada-Hachimantai National Park. The steep-sided, crystal-clear lake rates as one of northern Honshū’s top tourist attractions, but for many visitors the real highlight is the approach over high passes and along deep, wooded valleys. Though there are four main access roads, the most attractive route is south from Aomori via the Hakkōda mountains, Sukayu Onsen and the picturesque Oirase valley. For this last stretch it’s the done thing to walk the final few kilometres beside the tumbling Oirase-gawa, and then hop on a cruise boat across to the lake’s main tourist centre, Yasumiya.
Many roads around Towada-ko are closed in winter, and public buses only operate from April to November. During the season, however, there are regular services to the lake from Aomori, Morioka, Hachinohe, Hirosaki and (to the south) Towada-minami, a station on the line between Ōdate and Morioka. It’s best to buy tickets in advance on all these routes.