Stock Ghyll Force is the easiest rewarding walk from Ambleside: a short climb from the town centre into a wooded ravine where the stream drops in a series of falls. It is not remote, but it feels like a quick escape from the outdoor-gear shops and coach traffic.
The path can be slippery after rain, which in Ambleside is a normal condition rather than an exception. Go early or late if you want it quiet; in the middle of the day it fills with visitors looking for a walk that does not require a map.