This photo, identified as "The Fairy Pools, Isle of Skye, Scotland," started circulating online in Oct 2013. It attracted comments such as "oh my this is beyond beautiful." In reality, the picture shows the scenic Shotover River in New Zealand, where the vegetation is a normal shade of green. The vivid purple color is completely artificial, achieved by means of a color filter.
Below, the Shotover River as it looks without a purple filter:
Although the purple-hued image is a fake, there is indeed a location on the Isle of Skye known as the Fairy Pools. It's a set of waterfalls along the River Brittle in the south of the island. It's a popular tourist attract.
The real Fairy Pools on the Isle of Skye (source: All That Is Interesting)