In April 1988 several members of CEO (Cuerpo de Exploradores de Occidente) offered to show us a fissure cave they’ve been exploring for years and whose bottom, they said, had never been reached.

An hour’s drive from Guadalajara brought us a hot, moist valley, thick with tropical plants including a strange, large, green, ribbed fruit called a bonete which grows on trees and tastes like a vegetable when cocked. Passing through a banana grove that looks like something out of Vietnam, we climbed a steep hillside to a gap in the rocky cliff above us. There, in shade of en enormous natural bridge, we found the entrance to a strange cave, which is located in volcanic rock, but which is not a lava tube.

The fissure ranged in width from four meters to a barely passable 30cm (one foot). We walked along the first level for about 50 meters and found three holes in the floor apparently leading to a parallel passage below us. With the aid of a hand-line, we reached this passage which seemed to end after about 30 meters. But from above us came the voices of Jesús and one of the mountain climbers, inviting us to chimney up to where they had found yet another level. With the help of another rope we all managed the climb.