Park in the car park near the town hall, school, and Brion church.
(S/E) From the village of Brion, head gently downhill to the north along the D129 which crosses Brion (if you are heading uphill, you are going in the wrong direction). Take the second small road on the right, Chemin de la Combe Reynaud (signpost), which leads more steeply downhill.
(1) When you reach the D518, cross the road, taking care of traffic, then take Chemin de la Poterie in front of you.
You will soon reach a sign for "La poterie": keep going straight on along the small tarmacked road. After a wide bend to the left, take the dirt track, which is also on the left.
The track comes out shortly afterwards opposite a very large shed, on a small road, which you then take to the left. Keep following this road all the way to the end, up a lovely valley below the village of Saint-Michel-de-Saint-Geoirs.
N.B. The IGN map is inaccurate here: your road does not go up to the left towards Saint-Michel-de-Saint-Geoirs, but continues straight on (as indicated on the track plotted on the map).
When you reach a crossroads, go straight on: the road climbs up steeply ahead.
(2) You will come out onto on a small road with a series of recycling bins on your left. Take a sharp right down Chemin des Arêtes with your back to the village of Saint-Michel-de-Saint-Geoirs.
The road takes you through a hamlet (Les Granges), where it is worth stopping to see the old walnut drying building on your left (it dates from 1902; this is part of the region of the Noix de Grenoble appellation).
You will soon reach a fork. There is no point taking out a coin, take the right hand path (Chemin de Magnin), which will take you up through the beautiful valley of Magnin until you come out at a walnut grove.
(3) Here the path is not obvious. Keep going straight on alongside the small gorge on your left. The path gradually becomes more visible again. It bears away to the right and leads over to a group of houses. Turn left onto a small road.
(4) At an electricity pylon you will see place name: "Les Arêtes". Take the path that leads uphill opposite you. It will soon reach the edge of a wood. Turn right, then shortly afterwards, turn left up the track. You will reach a first signpost ("Le Four" – Les Arêtes 0.1 km). Keep going straight on.
(5) 100m further on, you will reach a second signpost for "Les Arêtes.” Turn right here down a wide gravel track. You will be able to enjoy the views that gradually open up around you.
Now follow the Tullins-Vinay GRP footpath (Grande Randonnée de Pays – Long Regional Hike) until you reach the waypoint (9) (Red and Yellow waymarks). Before long you will reach a signpost for "Montolivet": keep going straight on. The track will take you past a memorial plaque for Louis Mandarin who often roamed the area (picnic area). You will reach the Croix de Baron crossroads (wooden cross).
(6). Take the dirt track that leads uphill opposite you. Before long it will reach a small tarmacked road, which you then take to the left.
Ignore a path off to your right (signpost for "Buisson Rond") and keep going until you reach the pass of Col de la Croix de Toutes Aures.
(7) When you reach the pass, carefully cross the D518 and continue opposite you, then take the second road on the right immediately afterwards (signposted "Brion" -D129). The road takes you straight through the hamlet of Grange Neuve. Ignore a path off to the left that leads to a house, and then take the next path on the left (there are materials stored on an embankment). Turn left again to climb up the hill. Ignore a path off to the right.
(8) On your left you will reach a viewpoint with an orientation board and a picnic table. After stopping to admire the view, continue straight on. You will reach the D156 leading up from the pass at Croix de Revorin. Take the grassy path on your right, which isn’t very obvious, but which will become clearer as you reach the copse. It then comes out onto a gravel track. Turn right, and then at the fork take the left-hand path leading uphill.
(9) You will reach a complicated crossroads. Take the path to the far right, leaving the GRP footpath.
Continue along a very flat, easy path through Mouillasson forest (a hundred metres off to your left is Chambaran nature reserve surrounded by a fence).
(10) You will reach another complicated crossroads (signpost "Le Plâtre"). Turn right. N.B. The path is very steep and in the space of a very short time you will descend all the altitude gained during the walk. The small road will take you back to the D129, where you turn right to reach the centre of Brion and the car park(S/E).
