BIEI: Withered white larches rise from the blue water surface at the Blue Pond, which has been illuminated in the darkness of night for an annual display running through April 21 in Biei, Hokkaido.
The artificial pond, a famous tourist spot in the area, was built to prevent mudflow disasters in the event of an eruption of Mount Tokachi. Aluminium compounds in the water are said to scatter light, making it appear blue. The lights are switched off at 9pm every day. - Japan News
