Tunstall Reservoir, above Wolsingham
The main picnic site pictured above has a car park and sits beside the Tunstall Reservoir. There is an excellent 3km walk around the reservoir which you will find HERE. Start the walk by turning left out of the car park and then left over the reservoir dam wall.
Approaching from Stanhope the Tunstall road is signed to the left by the secondary school near the entrance to Wolsingham. After a couple of miles pass the dam wall on your right and the car park is about 600 yards ahead on the right.