After three hours underground, the acetylene flame on my friend’s miner’s hardhat guttered down to the size of a pencil tip and he stumbled into the darkness ahead, scraping his cheek on the dark blue marble ledge which overhung the stream we were following.

The cave was the Gouffre Geant or "Giant Hole," near Carcassonne, France. It takes its name from its major attraction and the only part seen by most visitors: A chamber about 800 feet deep and 130 feet across — the largest known in Europe — viewed from a balcony constructed near the top of the hole. But my friend and I were among a dozen persons who had climbed down the wall of the hole and slogged through the stream which had created it during a 5-hour "subterranean safari." The hike — hundreds of feet below the surface of the earth, much of the time wading in the calf-deep stream which continues to carve the colorful cavern through the limestone-rich Montagne Noire — proved an excellent introduction to spelunking, the sport of cave exploration.

The conditions were similar to those any amateur spelunker might encounter underground: Sliding down the loose rock of a steep incline for 50 yards, crawling through narrow passages, wading in the river-all illuminated only by the flame flickering above our foreheads on the miners hardhats we wore. The most difficult part of the hike — descent of a sheer cliff about 100 feet high to the bottom of the mammoth chamber which gives the cave its name-was made via narrow scaffolding. Other steep sections of the trail were strung with heavy rope to which we snapped our safety belts. These advantages made it possible for the an inexperienced person like myself to make the trek, but it was not without danger: the slick, wet rocks presented no easy purchase and while a fall was unlikely to be fatal, there was no guarantee one would avoid a sprained ankle, broken bones or even a concussion. Using the light of my lamp, we caught up with Jose Fuentes, one of our two guides. "No problem," Fuentes said, taking the little wire brush attached to the helmet and scraping carbon from the jet of the lamp. He relit the flame and we continued our trek as if nothing had happened.

Part of the time we were walking in a narrow defile a few yards wide where the ceiling disappeared in darkness two or three stories above our heads. At other places, the cave widened to 10 yards or more and we walked on the gravel shore of the stream, pausing often to look the colorful formations displayed around us. Mounded above the marble ledges were swirls and folds of brown and beige, looking much like petrified chocolate mousse or the rumpled mass of a fringed curtain fallen on some abandoned stage. These masses had dripped from the ceiling or flowed from fissures in the side walls over the centuries in a still-continuing process. In some places hung stalactites no larger than a drinking straw; elsewhere larger ones zig-zagged towards the ground, shaped by air currents which force the slow drips of mineral-rich water in one direction part of the year and to the opposite side for the rest.