Greenburn Tarn or reservoir sits in the shadow of Wet Side Edge, Great Carrs, Swirl How and Wetherlam. Seemingly the tarn is inaccessible from any of these, but this is not the case, there are in fact a few off path options to get down to the tarn from the fellside below Wet Side Edge and also from Swirl Hawse. Should you be that way inclined, these make for interesting and more adventurous routes to the tarn. They also give a nice insight into the upper area of this generally deserted valley. Alternatively, it's easier to reach the tarn from Little Langdale by following the track past the ruined copper mines next to Greenburn Beck.
After a short period of good fortune, the mines weakened and cessed to operate altogether in 1917. Between that time and this not only the buildings, but in particular here, the dam has fallen into a state of disrepair and now does little to hold back the water. I guess we now have more or less what was the natural size of the tarn, albeit with a reminder that for a brief spell, man exploited and harnessed the energy of the water.