Start the walk at the hamlet of Bois du Fayan in Boëge (Chemin du Penaz). A few parking spaces are available.
(S/E) Heading due north, follow the path towards Rocafort Castle: after a climb up some steep slopes, keep to the right at a junction.
(1) A little further on, you’ll reach the site of Rocafort Castle, where you can take a short detour (it has been under restoration for some time by an enthusiast). Continue the route towards La Duaz. You’ll come to a beautiful viewpoint, offering a particularly fine view of the castle you saw just before.
(2) Continue the route to the right, heading uphill.
(3) At the junction, turn right towards Chez Dupuis along a path that is moderately visible. Shortly afterwards, cross a meadow, heading to the left, then take a path on the left that alternates between uphill and downhill sections. Continue until you reach the D50 road, which you follow to the left for less than 100 metres.
(4) Follow a path to the right, then to the left, towards Notre-Dame des Voirons (marked White-Red GR® Balcon du Léman) via a few steep slopes. A little further up, cross a forest track and carry on straight ahead until you reach a junction.
(5) Carry on straight ahead, over a few more steep slopes. You’ll arrive at the site of the Notre-Dame des Voirons Chapel.
(6) Go round the chapel to the left and continue south-south-west, following a steep path at the start. A little further up, you’ll reach the Signal des Voirons (the highest point of Les Voirons).
(7) Carry on for a few dozen metres to an orientation table, where you’ll enjoy unobstructed views both to the east and west.
(8) Carry on straight ahead along the ridge, following the red and white GR® markings. You’ll reach another lovely viewpoint at a place called Saut de la Pucelle. Take care as there is a cliff very close by.
(9) Continue southwards downhill until you reach a junction with a path; take this path to the right. You’ll reach a crossroads at the Col du Prieuré (a lovely viewpoint).
(10) Continue straight on along the GR® route. A little further up, you’ll come to a junction with signposts.
(11) Turn left to reach the nearby Pointe de Brantaz (a lovely viewpoint on the eastern side). Retrace your steps.
(11) Continue left, heading due south, along the GR® route. You’ll reach another junction at a place called Pas de Marcy.
(12) Carry on straight ahead for a short while, then follow an ascending path (marked in white and red) over a few steep slopes. You’ll reach the summit of Pralère (a lovely view to the west if you veer off the path to the right).
(13) Continue down the path, which includes a few steep sections. You’ll reach the Col du Pralère (a junction of several paths) in a relatively short time.
(14) Turn right (south) and you’ll soon reach a promontory topped by a wayside shrine, offering beautiful panoramic views.
(15) Retrace your steps back to the pass.
(14) Leave the GR®. Continue straight ahead along a forest track (direction indicated by signposts). After an uphill section, the track descends gently before tackling steeper slopes. You’ll reach a large clearing at the end of a forest road.
(16) Follow this for about 800 metres, enjoying some lovely views along the way.
(17) At a junction, turn left onto the forest road, which then continues as a forest track. You’ll come to a small, isolated house on the right.
(18) Carry on along the path and, a little further on, turn right for a descent down a few steep slopes. You’ll come to a footpath further down.
(19) Continue along this path to the left.
(20) Shortly afterwards, take the path on the right at a junction (there are some ruins on the right): you’ll begin a long descent down some steep slopes, including a short, particularly steep section. You’ll reach the hamlet of Chez Novelly (marked as Novely on IGN and OSM maps).
(21) Follow the small road to the bottom.
(22) At the crossroads, follow the road to the left.
(23) After the Pont de Manant, continue along the road to the right until you reach the junction, then turn left to return, in a short while, to the car park (S/E).