Show cave

A show cave—also called tourist cave, public cave, and, in the United States, commercial cave—is a cave which has been made accessible to the public for guided visits.
A show cave is a cave that has been made accessible to the public for guided visits, where a cave is defined as a natural occurring void beneath the surface of the earth, per the International Show Caves Association.
A show cave may be managed by a government or commercial organization and made accessible to the general public, usually for an entrance fee. Unlike wild caves, they may possess regular opening hours, guided group tours, constructed trails and stairs, color artificial illumination and other lighting, musical/video/laser shows and concerts, elevators, small trains, and boats if they contain underground water features. Some caves (mainly in Asia) open to the public have temples, monasteries and religious statues or monuments. Some caves are visited by millions of tourists annually.
The term is used inconsistently between nations: many countries tend to call all caves which are open to the public show caves or public caves in contrary to all other caves which are not allowed to enter. However, there are many such caves which are not developed with trails, light and tours, which are visited by very many people. This kind of cave is often called a semi-wild cave. Access may involve anything between an easy stroll and dangerous climbing. Most cave accidents happen in this kind of cave, as visitors underestimate the difficulties and dangers.
The oldest known show cave in the world is probably Reed Flute Cave in China with inscriptions from 792 in the time of the Tang dynasty. Other old show caves are Postojna Cave in Slovenia, with the presumed first record of a cave tour in 1213. Other early show caves are Jasov Cave in Slovakia with inscriptions from 1452, the Sontheimer Höhle in Germany which was reportedly visited by Herzog Ulrich von Württemberg on 20 May 1516 and Vilenica Cave in Slovenia where entrance fees were taken from 1633 on. In 1649, the first "authorized" cave guide started guiding Baumannshöhle in the Harz in Germany though this cave was intensively visited much earlier.
The development of electric lighting enabled the illumination of show caves. Early experiments with electric light in caves were carried out by Lieutenant Edward Cracknel in 1880 at Chifley Cave, Jenolan Caves, Australia. In 1881, Sloupsko-Šošůvské Jeskyně, Czech Republic, became the first cave in the world with electric arc light. This light did not use light bulbs, but electric arc lamps with carbon electrodes, which burned down and had to be replaced after some time.
The first cave in the world with electric light bulbs as we know them today was the Kraushöhle in Austria in 1883. But the light was abandoned after only seven years and then visited with carbide lamps for decades. Today the cave is guided with handheld LED lamps. In 1884, two more caves were equipped with electric light, Postojna Cave, Slovenia, and Olgahöhle, Germany.
Because of the unwanted development of lampenflora (algae attracted to heat and light) around incandescent electric lights in show caves, many of these attractions, such as Ingleborough Cave in England, have switched to cooler-temperature LED lighting.