There was a cold snap in the air and snow on the ground when I arrived at my inn, a modest lodging in Shima Onsen, a hot spa town in Japan's Gunma Prefecture.
At first, I was puzzled about a curtain of green nylon webbing at the edge of the spring's elevated rotenburo (open-air bath), which partially obscured the view of a stunning valley. Then I spoke with a fellow bather. "They put the nets there to stop monkeys entering," he explained. "They like a good, healthy soak, especially at this time of year."