Galleny Force Waterfall.
Before leaving Lake District after a whole day of hiking day before, I have been told of this small but beautiful natural swimming pool. It is an ideal place and just brilliant pool to jump into on a hot day. Unfortunately it was not hot enough of a day for my liking, and since I was there on my own it would have been a bit awkward and not safe.
If you are going towards these sites in Lake District I definitely advise on staying at the Stonewaite camping site and having a dip on a lovely summers day.
Here is the location on the map.