Fernworthy Reservoir is a beautiful area to walk - there is a circular walk around the reservoir which takes 1-2 hours depending on how often you stop to take in the view! It can be muddy in places after rain, so be prepared. There is a short trail suitable for people with reduced mobility, but not suitable for wheelchair users unless you have a srong pusher and it has been dry for some time!
You can also walk through the forest surrounding the reservoir - one trail is way-marked, but most of the other tracks leading off the road can be explored and turned into your own circular walks. There are several historical stone rows and hut circles to find in the forest.
The carpark near the beginning of the forest is pay & display, and has seasonal toilets (April - October), but you can go on around the lake to other free parking laybys. At the far end of the road, there is a small parking area - leave it by the main track, and go steadily uphill to come out on the open moor, where you can then walk for miles.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.