At S. Marcel is a notable cavern that may be visited from the village or from the river, near the bank of which is a lodge for the man who undertakes to act as guide through its halls and galleries, and illumine them with Bengal lights. The grotto was discovered in 1838 by a man in pursuit of a rabbit. The cavern extends for several kilometres underground, and is rich in stalactites and stalagmites. The main gallery was the channel of an ancient river formed by the drainage of the fissured causse of Bidon and S. Remèze. This corridor, which is without incrustations, leads to le Balcon, a vertical wall thirty feet high, over which the ancient river fell in cascade. This is surmounted by an iron ladder. The second portion of the cavern consists of another long gallery conducting to the Forêt-Noire, a stone cascade of sixty feet, up which one mounts by a second iron ladder, to attain to the third portion of the cave, the Cathedral, where is the finest group of stalagmites in the whole grotto. Two more ladders lead to the Catacombs, a chaos of blocks fallen from the roof, and remarkable for its "bassins de dentelles," or "gours"—that is to say, a series of basins as holy-water stoups, formed by incrustations. I will let M. Martel describe them:— "Here begins one of the most curious and admirable stalagmitic formations to be found in these caverns. Imagine if you can a series of irregular basins set in the wall and superposed in retreat one above the other, forming steps—they are of various widths and depths, from a few décimètres to several mètres—their walls so transparent that they allow the light of the candles put in them to shine through. Their lips are capriciously twisted like writhing serpents, and they are lined with minute needles and tiny prisms of carbonate of lime, as delicate in their details as the antennæ of polypi, all either white, yellow, or rose colour, forming all together a vast pyramid of water-basins in onyx set with diamonds."[8] Further ladders and galleries are traversed, and more splendid masses of stalactite and stalagmite are seen. Formerly there were collections of these in the outer galleries, but they were wantonly destroyed by the peasants and by visitors. This cavern was anciently occupied by man not only in the prehistoric age, but later, for Gaulish black pottery has been found in it. I may add that on the Causse Grand Champ and on the Champ Vermeil are dolmens. An _aven_ of a really appalling character is that of Vigne Close, near the hamlet of Fontlongue. It was explored by M. Martel in 1892, and descends 575 feet into the bowels of the causse, or grasse, as the limestone plateau is here called.