Park at Col des Portes.
(S/E) Take the road heading north towards the Citadel (wooden signs at the top of the first climb). Take the yellow path on the left that runs along the cliffs.
(1) On your left, you will see a large cairn of dry stones at the foot of which is a flat stone bearing the inscription "La Citadelle " painted in yellow. Leave this path.
Face north-east, with a quarry damaging the top of a hill in the distance in that direction. Head right in that direction to reach the bottom of the valley. Weave easily between the copses and reach the bottom of the valley. Even if it seems blocked by shrubs, you can always find wide passages without any notable difficulty. You will then arrive at a long, uncultivated field bordered by trees. Walk across this field to the end, following a long, gentle slope.
(2) At the end of the field, do not take the track marked with wheel tracks that climbs to the right, but turn left into a small country lane that descends very gently to another field similar to the previous large field. Turn right as you descend. You will end up in a huge field at the bottom of which you will see the large building of the Sinne Observatory.
(3) Join the dirt track at the end of the field and head left towards the building, leaving the dome of the astronomical observatory on your left.
(4) Go through a metal gate, leave the track on the left and continue straight ahead. At the next crossroads, continue straight ahead (neither right nor left), wooden signs will show you the Lambruisse track. Stay on the large dirt track, ignoring the other paths.
(5) At a hairpin bend in the track, signs saying "chasse gardée" (hunting ground) and "propriété privée" (private property), as well as a metal cable stretched across the path, will direct you onto a dirt track in the forest. It starts off to the right and then immediately turns left, heading north along a short, fairly steep descent. You will pass hunting huts. After the last descent, you will cross another metal cable in front of you.
(6) Head left, towards the west, on a path that leads to beautiful meadows. At the bottom of the small valley, walk along the meadows towards the west until you reach the large building at Lambruisse. A small spring, a sheepfold and an old dry stone hamlet make this the perfect spot for a snack.
(7) Leave the old building by taking the dirt track on the right that runs alongside the fields and narrows towards the west.
(8) About 400 metres after the farm, turn right at a wooden post. A path crosses the fields and runs alongside the forest. The fields are now on your left.
Head up the valley towards the west and join the wide dirt track that climbs slightly.
(9) About 150 metres before a hairpin bend, turn left. Avoid going all the way to the fork by cutting across the scrub; you can clearly see the path just above. Join the track and climb left to the top of the hill. After two slight bends, you will find a gate made of metal logs on the ground on your left.
(10) Turn left onto the long straight stretch. The track curves slightly to the right to form another long straight stretch. At the end of this stretch, pass the metal logs again and, 500 metres further on, you will come to a large sharp bend that climbs slightly towards the north-east.
(11) Leave the track exactly at the bend in the road and head south for 100 metres through the bushes (no difficulty). Cross a track marked by wheel tracks, taking neither the left nor the right, and continue through the scrub in the same direction. Leave several paths on either side and arrive at the edge of the cliff. From there, you will see an electricity pylon on the ridge.
Head towards it along the cliffs to reach the highest point (the Citadel).
Take in the most beautiful view of the walk, continue along the cliffs and you will come to a crossroads you passed on the way there.
(1) Turn right and take the same path as on the way there to return to your vehicle (S/E).
