Park at the Col des Portes car park between Vauvenargues and Rians.
(S/E) The trail starts at the south-east end of the car park. Take the path that runs alongside a pasture, then enters a small valley.
(1) Cross a forest path and take the path opposite, marked by two cairns.
Blue markings
Continue along this path until you reach a passage in the enclosure, then turn left after this passage to reach a forest path.
(2) Turn right onto this path, which will take you to the Malivert Oratory.
White and redGR® markings
(3) Take the path marked Pic des Mouches behind the oratory. This path will take you to the ridge and follow it to Pic des Mouches.
(4) Retrace your steps for about a hundred metres.
Red markings
Turn left onto the red-marked trail that goes around Garagaï de Cagoloup before descending towards Col des Portes.
(5) At the departmental road, cross it and continue straight ahead.
Yellow or blue markings
(6) When you reach a large plateau, a sign indicates the direction of the Citadel, to the left. Follow this sign.
(7) Pass the remains of dwellings, including the foundations of a chapel. Continue north-west to reach the remains of the Citadel's walls.
(8) Cross the enclosure and you will come out onto the plateau. Walk along the plateau to the northern enclosure, then follow it north-east until you reach an opening. The path continues without much difficulty until it joins a DFCI forest track.
(9) Turn right to reach the Sinne Observatory.
(10) After the dome, turn right onto the path and continue straight ahead (south-east) to reach the Col des Portes car park (S/E).