Lake Chuzenji lies at about 1,270 metres in the mountains above Nikko, and it was made by a volcano. Some twenty thousand years ago, Mount Nantai, a steep cone that now rises to nearly 2,500 metres on the north shore, erupted and its lava dammed the Daiya River, forming this long, clear, deep lake. The water is cold, even in summer, and it is stocked with trout and salmon, and the lake is surrounded by forest. Seen at dawn, with mist rising from the surface, it is a calm and lovely sight.
In the late nineteenth and early twentieth centuries, foreign diplomats posted to Tokyo escaped the summer heat by building holiday villas on the shore, and two of them, the former British and Italian embassy villas, have been restored and can be visited. The sailing and rowing boats on the lake, and the old wooden hotels, recall those times. Utagahama, on the eastern shore, is a pleasant beach for a stroll, though the water is chilly for swimming, so the label's swim is optimistic unless you are brave.
Nikko has its great shrines and temples, particularly the Toshogu, the elaborate mausoleum of the first Tokugawa shogun, set among old cedars. The plateau of Senjogahara, to the north-west, is a wide marsh with walking paths and clear views of the surrounding mountains, and is worth exploring if you have time. The Kegon Falls drain the lake dramatically at its eastern end.
The ride up is by the Irohazaka hairpins, and the road along the shore is easy and scenic, with views over the water and the mountains. In autumn, traffic is heavy, with long queues, so plan for a very early start. Summer is cooler than the lowlands, and winter brings snow and ice, which can close the roads.
As a finishing point it is hard to beat: a mountain lake, a hot meal and a bath.