Tucked beneath the towering rock walls of Great Gable in England's most remote valley, the Wasdale Emerald Pool sits in a natural mountain amphitheatre fed by twin waterfalls.
 
The water clarity here is unlike anything else in the Lake District. This insider guide covers the honesty fridge hidden on your return route, the secret fairy pools most walkers march straight past, and the precise midday light window that turns the water a vivid turquoise.
 
Worth every step of the forty-minute trek.