Japanese photographer Kent Shiraishi is the author of a photograph that's now known to millions as the background wallpaper to OSX Mountain Lion—the counterpart to Windows XP's rolling green grass fields. But while most of us know Shiraishi's photo, not as many know the fascinating story behind it.
Blue Pond is located in Biei, on the Japanese island of Hokkaido, roughly five miles away from an active volcano called Mount Tokachi:
Sited directly on the ring of fire, Tokachi is a formidable and lovely spot, meaning there's plenty of development around it. And in 1989, the town's government staged an ambitious infrastructure program to protect Biei from the incredible damage that lava and mudslides could cause after an eruption. That included damming up sites like this one, creating ponds in the process:
Blue Pond receives so much attention because of its shimmering blue hue—which changes into a lovely green in certain light. According to Spoon & Tamago, the effect is caused by water containing a colloid—a microscopic mixture—of aluminium hydroxide, a naturally occurring mineral that's used to make antacids. Those particles reflect blue light (a similar phenomenon to what makes the sky blue) quite well, which means they change dramatically with the light.