The last stage of this journey in Chalosse and Tursan takes you to the gates of the Gers, to Aire-sur-l’Adour, via the small village of Duhort-Bachen, a former bastide with a church, a miraculous spring and a castle. Push on to the Château du Lau, admire its glazed bricks and typically Flemish architecture.
 In Aire-sur-l’Adour, a large village straddling both banks of the river whose origins are lost in antiquity, the religious heritage buildings are worth a visit: the cathedral of Saint-Jean-Baptiste, built in the 11th and 12th centuries, imposes its mass in the heart of the village while on the heights, in the Mas district, stands the church of Sainte-Quitterie which houses the magnificent white marble sarcophagus of Saint-Béat of the Visigoth princess Quitterie, decorated with sculptures from the 4th or 5th century. A must for pilgrims on the Via Podensis.