La Traversée des Vallées is a semi-nocturnal trail event held in Longueville-sur-Scie, Seine-Maritime, with start and finish lines in the village. It features three trail distances: 28 km with 540 m of elevation gain, 22 km with 400 m, and 11 km with 210 m. An 11 km nature hike, also with 210 m of elevation gain, is available for those who prefer not to race.
The event's format is practical and community-focused. Participants require a headlamp and reflective gear, suiting the semi-nocturnal nature of the course. Facilities include a gymnasium, changing rooms, showers, toilets, medical support, and parking for cars and bicycles. A complimentary childcare service is offered for runners' children, requiring on-site registration. All participants will receive a commemorative item. Entry fees are reasonable, ranging from 8 euros for the hike to 20 euros for the 28 km race.