Lake Onuma

Lake Onuma sits in the caldera of Mount Akagi in Gunma Prefecture, one of three volcanic lakes on the mountain. The lake is small and deeply colored, and the trail around its rim takes about an hour on foot through deciduous forest that burns red and gold in October. Rowboat and pedal boat rentals are available from the lakeside in warmer months, and in winter the frozen surface supports ice fishing for smelt. The wider Akagi plateau has hiking trails connecting the three calderas, and the mountain road up is a well-known cycling route. The Akagi Shrine sits on the western shore, reflecting in the still water on calm mornings.