This is a worth-it destination run! Drive 11 miles west of Derry to Burt Castle, the relatively intact remains of an old castle surrounded by farmland. Near there is a lovely path near there that runs along the Drongawn Lough for nearly 3 miles. It’s a flat, wide, gravel path, with great views of the water. An out and back is 5.7 miles. Note: can be muddy/soft.

Kenneth Allen / Burt Castle / CC BY-SA 2.0

For more, there are lovely, relatively traffic-free routes around Burt Castle. Rolling hills, farmland, and a pastoral feel. Note that these roads can be narrow and have no shoulder or sidewalk. Use caution!