Park on the right-hand side of municipal road No. 5, at the GPS coordinate, just past a (rather weathered) sign describing the walk.
(S/E) Follow the road heading due south until you reach a barrier (a chain blocking access to cars).
(1) Go past it and continue straight ahead. Walk along a very well-maintained track with a steady gradient; there is only one possible route, so there are no particular navigation difficulties. After several bends, the track turns westwards and reaches a junction (IGN elevation 217).
(2) Continue to the right along the main track, which heads north until you reach the Poindimié mast and its panoramic view of the lagoon.
(3) Turn back and head back to the previous junction.
(2) Take the path branching off to the right. This section is less well-maintained, with quite a lot of tall grass, but nothing impassable. Hiking trousers may be useful on this stretch. There is only one possible route again, so there are no navigation difficulties either. Continue until you reach the point near the Napoémien mast.
(4) Enjoy the panoramic view over the valley and the sea, then follow the outward route in the opposite direction back down to the car park (S/E).