The starting point is on the Bavella road, the D268, shortly after Zonza and its racecourse, after a hairpin bend on the road up to Bavella at about 250 m. Park on the opposite side.
(S/E) Take the forest path that climbs to the right of the road (when climbing to the Col de Bavella) and turn onto the small path that climbs immediately to the left just after the barrier. You will reach a crossroads of tracks and paths at the Fontaine d'Argazavu.
(1) Continue along the path on the left and reach the Velaco stream.
(2) Cross it, then turn right at 180° and follow a good blue-marked trail, but be careful as the markings on the rocks are very sparse. You will come to another river, which is not shown on the IGN map but is clearly marked on the OSM map.
(3) Cross the river and head right (maze of dead trees and rocks). The direction is a little confusing at first, but follow the bed of the same stream without crossing it, keeping a north-east direction. You will come out at the Col de Fumicosa.
(4) Follow the same route in reverse to return to the car park on the D268 (S/E).