A great piece of local history, and some informative plaques all nicely painted. Fisher Tarn Reservoir was at one time an important part of Kendal's water supply. It's since been superceeded by more modern systems and is now primarily used for fishing. Worth a stop to admire the turrets and arches, and read the plaques.
The cache is a simple mag micro. A drive-by but a pleasant stop on the old road to Kendal. There are good views and another cache a short way further west, see GC1GYJ4.
Enjoy!