The route crosses the final stretch of Gascony, leaving the Gers department and entering the Landes. The landscape shifts as oaks and chestnuts gradually give way to maritime pines and the soil becomes sandier.

Aire-sur-l'Adour sits on the river Adour, which rises in the Pyrenees and flows to the Atlantic at Bayonne. The town has a Romanesque cathedral and a tradition of bullfighting (courses landaises) using athletic vaulters rather than killing the bulls. The arena hosts events during summer festivals.

Look for the Tursan wines from the nearby vineyards, a little-known appellation producing crisp whites from the Baroque grape.