Starting at the Niolon's train station walk to the end of 'Chemin des Poseurs' and enter the trail. From the start, leave the first viaduct behind you and follow the valley uphill due nprth-west.
After the small bridge, follow the cliff slope to the left, you'll reach the fort of 'Niolon Haut'. Follow the ridge through the small trail to catch up with the large wide track. After approximately 800m, on a right-hand curve, follow the trail on your left-hand side, going down to Erevine's valley. Once at the bottom, go through the pedestrian tunnel and head to another viaduct. Erevine's beach is located right underneath, with a stunning view of the Erevine's island.
Just after the tunnel, turn right to climb over the rocks and follow the rail road tracks. There's no danger. Keep going until you get to the small Mejean harbor.
For the way back, use the same path to return to the beach. From there, a trail on the right-hand side is winds around the edge of the cliff, reaching Riflard's cove (Calanque du Riflard) then Jonquier's cove (Calanque du Jonquier). Once you get to the first viaduct seen at the beginning of the hike, turn left uphill toregain the trail in the valley. Turn right to get back to the train station.