Tourism. Nature destination: the most beautiful routes around Grenoble, between mountains and valleys

Want to get some fresh air, exercise, recharge your batteries or discover new places with family or friends? The Grenoble metropolitan area has 865 km of marked trails across its 49 municipalities, some of which are even accessible from Grenoble on foot, by bike or by bus.

Registered in the Departmental Plan of Walking and Hiking Routes (PDIPR), these paths, intended primarily for walking, can also accommodate mountain bikers, trail runners and even horse riders.

It is therefore important to "be vigilant and tolerant on these trails," states Grenoble Alpes Métropole (GAM) on its Walks and Hikes map. Free, it presents all the routes and 30 topos.

To complete the network of trails around the Bastille, it will now be possible to reach the Mandrin caves located next to this emblematic military building from the town hall of Saint-Martin-le-Vinoux.

Climbing through the forest to the Bastille drawbridge, this mountain trail offers beautiful views of the Vercors and the valley.

Arriving at the drawbridge, the route takes the path which, passing under the road wall, leads to the entrance to the so-called Mandrin caves .

The site is an ideal spot to discover the capital of the Alps and its mountains.

To also decipher the evolutions of the city, long corseted before being freed from all its walls and, boosted by the organization of the 1968 Olympic Games, to take its ease towards the south.

Several trails lead hikers, joggers, and tourists to its summit. With its flowerbeds and rock-cut staircases, the climb through the Jardin des Dauphins is quite pleasant, and the descent through the Casemate offers another viewpoint if you want to do a loop.

"But be careful, the Dolphin Garden closes in the evening," reminds Cyrille Crionnet. Open all year round, it is closed from 9 p.m. to 8 a.m.

Much easier because it's completely flat, the water trail between Sassenage (Ovalie Park) and Noyaret (town hall) is also passable all year round. And the walk is educational.

Ten totems punctuate this thematic trail, which crosses the various waterways over a 6-km stretch. It first runs alongside the Furon Canal, then briefly along the Isère River at the Saint-Égrève dam (totem 6) before heading into the market garden plain fed by the Pierre-Hébert stream and reaching the village of Noyaret. Ideal for families on bikes.

Also on foot with the possibility of returning by bus (Proximo line no. 20).

Much shorter (2.7 km) but just as easy and accessible year-round, a hike starting from the Désert de Jean-Jacques Rousseau between the village of Seyssinet and La Tour sans Venin on the D 106 near the Château de Beauregard (T65 Grenoble/Lans-en-Vercors bus stop and large parking lot).

The only drawback is that, although it was a place where Jean-Jacques Rousseau strolled during his stay in Grenoble in the summer of 1768 – hence its name – the site is anything but deserted today. Popular with families, it is a place to relax with a picnic area and educational panels on the nature and origins of the site.

Once you enter through the large gate of the Désert, a park surrounded by a stone wall, the first part of the route to Pré Faure is largely between cliffs. You can return via the Désert de l'Écureuil, another dry gorge in the Bois des Vouillants.

Other trails allow you to extend your outing. For example? An additional 2.4 km loop to reach, from Orée du Bois, the ruins of the Froussard farm (destroyed as a result of resistance) and then return to Pré Faure.

Not far from there, the Via du Tram route invites you to discover, between the old Pariset station and Saint-Nizier-du-Moucherotte, the remains (tunnels, walls and gently sloping routes) of this old Grenoble/Villard-de-Lans (GVL) tramway line.

The return trip can be made via the GR9 route, completing a loop of a total of 6.6 km. But to complete the Via du Tram (Grenoble/Saint-Nizier, 38 km) on foot or by mountain bike, you'd better have strong calves.

Still on the Vercors hillsides, Comboire hill, located between the communes of Seyssins and Claix, offers a great alternative to hikers who love history and unspoiled nature, with its old military fort and its communal sensitive natural area (ENS).

A 5.5 km loop with a 250 metre elevation gain starting from the Pré Nouvel park (Seyssins) allows you to discover this island of nature with oak forest, southern flora and long limestone cliffs sheltering eagle owls and peregrine falcons.

The trail follows the ridge of Comboire Rock to its belvedere with a view of the town. The return is via the Col de Cossey (430 m), the Chenaie and the Travers.

The Haute-Jarrie Pond Regional Nature Reserve and its interpretive trail are also ideal for a lovely walk or mountain bike ride through the Combe de la Gouterie, starting from the Robert Buisson Park in Échirolles. However, you'll need to leave your bike at the entrance to the reserve.

Several routes are possible, for a beautiful hike of 8 to 11 km with low elevation (250 m) on the Champagnier plateau (a plateau also appreciated by horse riders).

The city, which manages the reserve, organizes a free monthly guided tour from February to October, upon registration. The next date: July 27, for dragonflies.

Further south, the aptly named “Belvédère de Vizille” walk (6.6 km, 330 m elevation gain) offers a wide view of the town and its castle , the Romanche valley, the Connex and the eastern balconies of the Vercors.

From the Allas bridge, this viewpoint located at an altitude of 550 meters can be accessed by climbing (a fairly steep path) after following the path along the walls of the castle garden, or by descending by taking the loop in the other direction.

The walk then starts on the GR738 for 1.2 km before branching off at Barontes onto the path leading to La Feyloulaz and then the belvedere.

But a variation is possible by continuing the GR738 to Mont Sec, a pretty hamlet with stone houses and a communal oven, located at an altitude of 1,500 meters before descending to Bouvrère (805 m) then joining the belvedere loop at La Feyloulaz.

There are many other routes to discover, some even for an ultra-easy walk like that of the Fontaine ardente, one of the seven wonders of Dauphiné, starting from Gua (600 m round trip, 70 m elevation gain).