This hike consists of a loop to discover the Catalan orris and natural fountains before reaching the chapel of Notre-Dame du Château, one of the high places of Sorède, at the foot of the ruins of the Castle of Ultrera. Then go on the historical traces of the solar furnace before going back down, visit with its founder, the new solar furnace of Sorède, faithful replica of history. Altitude difference 600m / 13 km; duration: 7h including visits. Meet at 9 am in the car park of the festival hall of Sorède (Salle des fêtes, rue de la sardane). Provide good shoes, lunch and enough water. Information and reservations at the Tourist Office Laroque des Albères.