This reservoir in Blackburn is a nice place for an easy stroll in the town.
You can find it next to Guide Reservoir to the south of the town centre. There's some nice trails along part of the water but can get a bit muddy in the winter months. There's good views from the grassy path to the surrounding hills and countryside.
To continue your walking in the town head north to pick up the Leeds and Liverpool Canal and enjoy a stroll along the towpath. The Witton Weavers Way could also be followed to the viewpoint at Billinge Hill on the western side of the town.