Lake Towada - on the border of Aomori and Akita Prefectures - is one of Japan's most scenic spots. The large, double caldera lake is part of a national park. It is surrounded by deciduous broadleaved forest, which bursts into a riot of color in the fall. Kosaka is about 40 minutes by car from the lake. The old mining town was once prosperous. The town's many elaborate buildings, blending Western architectural elements, are a testament to its affluence. On Journeys in Japan, we explore the nature around Lake Towada, old copper mines and unique 20th-century architecture.