Aulas, now a small village, was in the thirteenth century the chief town of the barony of Hierle; and in 1621 it was one of the five most important places in the district devoted to the principles of the Reformation, that was fortified by De Châtillon, grandson of the Admiral Coligny. Castle and walls have fallen; they were levelled after the peace of Alais. Just beyond Aulas is the Château de Clapisse, in which was born, in 1740, Henri de Celadon, Chevalier de Lanuéjols, noted for his periodic duels. M. de Celadon left home every year on a fixed day and took his way to the Isle of Basthellasse in the Rhône, near Avignon. At the same time, annually, another gentleman left Lyons, and made his way to the same spot, from which one or the other returned wounded. This continued for twelve years; but on the last De Celadon must have inflicted a more than ordinary wound, for on the thirteenth visit to the isle, in the following year, his adversary was not there. He withdrew, but in the fourteenth year returned, and again he with whom he had crossed swords twelve successive times was not there. Then he instituted inquiries, and ascertained that his foe had died two years previously. What the cause of the long-protracted quarrel was never came to light; De Celadon, who died in 1810, carried the secret with him to the grave. The source of the ravine of that strange river, half subterranean, the Vis, is best visited from Le Vigan. The Vis, a river as large as the Hérault, where it effects its junction with the latter, rises at S. Guiral, near the frontier of Aveyron. It passes Alzon, flows below the sheer limestone escarpments of the Larzac, and receives the immense spring of the Foux, after which only does it become a river; passing between the rocks of Tude and d'Aujean it traverses a fine ravine. Montdardier (_mons arduus_) is five miles from Le Vigan, and to reach it the Causse has to be passed under from Avèse. Here the limestone is so compact that it can be exploited as lithographic stones. Much of the way is shaded by chestnuts below the white escarpments of the rocks of La Tude and of the Pic d'Anjeau, forming the edge of the Causse de Blandas, an islet of limestone separated from Larzac by the Vis, as is also the much smaller islet of Campestre, that lies between the Vis and the Virenque. These causses are strewn with dolmens and bristle with menhirs. The Castle of Montdardier, that has been restored by Violet le Duc, occupies a well-timbered height above the little stream that joins the Arre at Avèze. The village clusters about the hill, the extremity of which sustains the castle and the park.