Pontoise has 1 trail including medium difficulty trails. The trail with the highest elevation climb is GR 1 and the one with the least climb is GR 1. The longest trail is GR 1 at 121 km. To complete this hike you should budget at least 6 days. For a shorter adventure you can try GR 1 at 121 km. This could be done in as little as 6 days. Trails with the best offering of hostels include GR 1.