when were the lascaux caves closed to the public
Lascaux On September 12, 1940, the entrance to the Lascaux Cave was discovered by 18 year old Marcel Ravidat. Ravidat (died in 1995) returned to the scene with three friends, Jacques Marsal, Georges Agnel, and Simon Coencas, and entered the cave via a long shaft. The teenagers discovered that the cave walls were covered with depictions of animals.[7][8] Galleries that suggest continuity, context or simply represent a cavern were given names. Those include the Hall of the Bulls, the Passageway, the Shaft, the Nave, the Apse, and the Chamber of Felines. The cave complex was opened to the public on July 14, 1948.[9] By 1955, carbon dioxide, heat, humidity, and other contaminants produced by 1,200 visitors per day had visibly damaged the paintings. As air condition deteriorated fungi and lichen increasingly infested the walls. Consequently, the cave was closed to the public in 1963, the paintings were restored to their original state and a monitoring system on a daily basis was introduced.
Cave of the Crystals The main chamber contains giant selenite crystals (gypsum, CaSO4·2 H2O), some of the largest natural crystals ever found.[1] The cave's largest crystal found to date is 12 m (39 ft) in length, 4 m (13 ft) in diameter and 55 tons in weight. The cave is extremely hot, with air temperatures reaching up to 58 °C (136 °F)[2] with 90 to 99 percent humidity. The cave is relatively unexplored due to these factors.[3] Without proper protection, people can only endure approximately ten minutes of exposure at a time.[4]