Time on foot: 1.5 hours. Distance: 5.74 km.
This route can only be done when the Darnius-Boadella reservoir is not full. The walk starts from Sant Llorenç de la Muga or by taking the road leading to the Riembau bridge and parking the car there. From the bridge onwards, we stroll along the edge of the reservoir tailwater, which will take us to where we can see, very close by, the remains of the Royal Sant Sebastià Foundry, that was in use during the 18th century and is now submerged in the water.