Park in the Col du Grand Ballon car park, to the left of the D431 when approaching from the south (on the chalet-hotel side).
(S/E) Opposite the chalet-hotel, turn right onto the Club Vosgien trail, marked with a Red Rectangle crossed by a White Rectangle. Then begin the descent towards Le Haag along the Route des Crêtes.
(1) About a hundred metres before the farmhouse inn, turn sharply left and climb towards the Grand Ballon, following the Red Rectangle markings. Take the famousGR®5to reach a Fork in the road in a slightly rocky area on this side of the Grand Ballon.
(2) Keep left towards the Monument des Diables Bleus and the summit (Red Ring markings). At the junction about fifty metres further on, turn left. Climb up to reach the monument.
(3) Continue in the same direction to reach the summit and the radome (radar).
(4) Cross the radome forecourt and head straight down (north-north-east) until you reach a three-way junction.
(5) Turn left towards the Chalet Hôtel du Club Vosgien (Blue Ring signposting). Enjoy the view of Lac du Ballon and continue to the car park (S/E).
A really lovely walk with breathtaking views. Partly on a path, then grass, then lots of stones, but it was well worth it