Start at the car park near the chip shop, opposite the DIY store.
(S/E) Exit Rue Marcel Sambat onto the main Pierre Curie road. Turn right for 200m, passing over the old lock.
(1) At the roundabout, turn left onto the towpath along the old Canal de la Deûle. Watch out for the many trucks serving the small industrial zone. Take the sidewalks. The traffic soon disappears and you'll be going along the canal for around 5km.
(2) Shortly after the canal divide, turn right up to the bridge (3). Cross the canal, go down the bridge and enter Billy-Berclau.
(4) Immediately turn left at the first road along the bridge, then right at the canal onto the towpath. Follow the canal for about 800m, passing under a bridge.
(5) Take the first right-hand path, which can be quite muddy. After 50m, turn right to join the road.
(6) Turn right onto the D39, cross the first bridge.
(7) Turn left to walk around the island. This little loop is optional but pleasant, and is about 800m long. Exit at the same end.
(7) Then turn left and continue on the D163, go down the bridge.
(8) Take the first road on the left. At the canal, follow the towpath to the right for about 5km.
(9) Go around the Écluse de Don (Don Lock).
(10) Just before the bridge, take a small tarmac track that joins the main road, where you turn left.
Pass over the canal, then return to the starting point along Rue Anatole France (beware of traffic) for approx. 500m. Turn right towards the car park (S/E).