A collapse in the limestone sea
The Gouffre de Padirac is a vertical gateway into a hidden hydrological network. The chasm itself, a vast hole 35 meters in diameter, is the result of a collapsed ceiling of a much larger, ancient cavern. This event, which occurred several hundred thousand years ago, exposed a section of a river system that had been chemically and mechanically carving its way through Jurassic limestone for one to two million years. The surrounding area, the Causse de Gramat, is a classic example of karst terrain. This type of topography forms when water, made slightly acidic by atmospheric carbon dioxide, dissolves soluble bedrock like the limestone that formed here 170 million years ago when the region was a shallow sea.
The process began with water infiltrating faults in the limestone plateau. Over millennia, this persistent erosion created a vast network of subterranean galleries. The Padirac River flows at the bottom of the chasm, 103 meters below the surface. Speleologists have so far mapped more than 42 kilometers of these passages, but only a fraction is open to visitors. The initial descent brings you to the level of the river, where the year-round temperature remains a constant 13°C.