From Castelculier the route rolls out past the river La Séoune, then follows the Garonne and the Gers on its way through the landscape. Along the way you pass the Château d'Escalup and the Réserve Naturelle de la Frayère d'Alose, with 72.1 km of riding and 529 m of climbing to keep the legs honest. The surface is almost entirely paved, so the wheels keep turning from start to finish. Back in Castelculier, the loop closes where it began.
