The Marais des Bidonnes

Park in the car park near the Rond-Point des Iles.

(S/E) Head towards the roundabout. Leave the roundabout on your right, use the pedestrian crossing to cross Avenue du Rond-Point des Iles (D984c) and follow it to the left. Cross the River Versoix.

(1) Immediately afterwards, take a path on the right and walk alongside the river on your right. Further on, take a small bridge over the river and then walk alongside it on your left. Note the access to a viewing point on the right; you will soon reach a junction.

(2) Turn left and walk alongside two small ponds on your right. Continue along a wider, unpaved track. You’ll come out onto a small road; follow it to the left.

(3) As you come out of the right-hand bend and just before the D384c, keep parallel to the road and walk alongside a field on your left. You’ll reach a roundabout.

(4) Then turn left and walk along Avenue du Pont des Iles.

(1) Carry on straight ahead. After about fifty metres, cross the avenue at the pedestrian crossing and you’ll immediately reach the starting car park (S/E).

Safety instructions
Part of this route passes through the Haute Chaîne du Jura National Nature Reserve; please respect its regulations

Among these rules: dogs are not permitted, even on a lead!

Before setting off
- Check the general and local weather forecast to ensure there is no rain.
- Find out about the approach walk, the altitude of the route, the walking time and possible escape routes (IGN map, GPS, guidebook, etc.).
- Assess any potential risks by consulting mountain professionals, mountain huts and lodges.
- Inform a friend or family member of your plans and contact them again if there are any changes: departure and return times, number of participants with each person’s telephone number, vehicle(s), car park.
- Avoid setting off alone; use equipment suitable for the activity, which is properly adjusted and in good condition, including a head torch, a fully stocked first-aid kit and a survival blanket, etc.
- In the event of a problem, call 112 (the European emergency number).

You can round off your hike by walking around Lake Divonne (3 km).