Les Costes is a village locality in the Champsaur, in the Hautes-Alpes, and today belongs to Aubessagne. It is no longer a separate commune: the new municipality was formed on 1 January 2018 from Chauffayer, Les Costes and Saint-Eusèbe-en-Champsaur. For the entire former commune, INSEE recorded a 2015 municipal population of 178, with five people counted separately and a legal total of 183. Those figures describe the former municipal territory, not a current standalone count for the village. The old name still points to a distinct mountain settlement, but municipal administration now serves the combined territory from Chauffayer.
The village's character is best read in its hedged fields and watercourses. Champsaur agriculture historically depended on small cultivated parcels, and the surviving bocage makes those boundaries visible: ash, birch and beech hedges break the wind, shelter animals and help limit erosion. The Parc national des Écrins notes that irrigation channels in the valley date back to the Middle Ages and were managed among water users. The channels and damp edges also support habitats for birds, insects and other wildlife. This is a working agricultural landscape, not a manicured park; paths cross private fields, so visitors should stay on marked routes.
A practical way to understand that landscape is the Sentier du bocage, whose trailhead is at Beaurepaire in Les Costes. The marked loop is 2.7 kilometres and very easy. The Park's route sheet estimates about 1 hour 30 minutes and roughly 40 metres of ascent; the tourism office lists about one hour and 42 metres, so check the current map and signs for the version in use. The track passes hedges and irrigation channels, follows a former road to Les Costes, and returns through Beaurepaire. Its wide, gentle path makes it a family outing, but a small stream crossing and seasonal conditions still matter. Snow, storms or runoff can alter access; confirm conditions with the tourism office before setting out.
Above the village, artificial Lake Roaffan offers a second, quieter stop. The tourism office describes mountain views, picnic tables, fire spots and parking, with access on foot from Les Costes or by car to the water. A separate 6.8-kilometre loop from the lake climbs through beech woodland towards the hamlet of Les Blachus, but its 250-metre ascent and moderate rating call for suitable footwear and a current route check. The lake's hours are not defined or guaranteed, and water or fire restrictions can change. Treat it as a simple outdoor pause rather than a staffed visitor site.
The parish church of Saint-Jean-Baptiste stands midway between Maisseret and Maissubert, reflecting the area's dispersed hamlet pattern. A date of 1848 is carved into its doorway; the Ministry of Culture considers that year likely to mark its construction, and records restoration in the last quarter of the 20th century. The single-nave church has two rib-vaulted bays, a vaulted apse and a two-bay bell gable. Inside, a 19th-century painting by P. Reynaud depicts the Holy Family with the child John the Baptist and Saint Anthony of Padua against a mountain landscape. It became a protected movable object in 2012. Check locally before expecting the building to be open.
For practical services, the Aubessagne mairie is in Chauffayer; the commune's site publishes contact details and current office hours, which should be confirmed before travel. The village's strongest visitor experiences are modest and place-specific: reading the farm hedges, following a signed loop, pausing above the rooftops at Roaffan, and noticing a parish church whose date is documented rather than legendary. Route information, weather and opening conditions can change, so verify them locally before departure.
