The Padirac Chasm is a cave located near Gramat, in the Lot department, Occitanie region, France. The chasm itself is 103 m (338 ft) deep, with a diameter of approximately 33 metres (108 ft). Visitors descend 75 m via a lift or a staircase before entering into the cave system. The cave contains a subterranean river system that is partly negotiable by boat, and it is regarded as "one of the most extraordinary natural phenomena of the Massif Central".
The chasm was created at an undetermined point in time when the roof collapsed into a large internal cavern. It is known that the cavern existed in the 3rd century, and was inhabited during the 15th and 16th centuries, when potassium nitrate was excavated from the area. Since the 1930s, visitors can access the cave system by descending 75 m by lift or stairs, and then exploring the chasm system on foot and by boat.
Padirac is the most frequently visited underground tourism facility in France, with more than 350,000 visitors annually, and a record of 460,000 in 1991.