Taken on my recent trip to the South Island, New Zealand. This is the Blue Lake in St Bathans (named for its distinctive blue colour caused by the minerals in the water). It was man-made by miners digging away at a 120m hill until all that was left was a 68m deep pit. When the mining stopped, the hole filled with water forming the lake. This is a single exposure, taken using a 2-stop graduated ND filter. Very little post-processing here, this was exactly how it appeared that morning.