Hummelstown. It opened to the public as a commercial attraction in 1929, and was operated by the Indian Echo Cave Company. Known as Indian Echo Caverns by the 1930s, the attraction was purchased in 1942 by Ed Swartz, who had grown up near the caves and visited them as a child. Swartz subsequently went on to build a business reputation as a country and western entertainment producer prior to purchasing the cavern system. During the early years of Swartz's ownership, Indian Echo Caverns offered both country and western concerts, as well as guided tours of the caverns. Visiting performers included Grand Ole Opry star Roy Acuff and the Hoosier Hot Shots from the Chicago National Barn Dance. Those performaces were discontinued in 1947 when attraction waned for the concerts, but rose for tourist visits to the caves. In 1971, Indian Echo Caverns was awarded the National Caves Association seal of approval and recommended to tourists as an attraction worth visiting. The entrance to the cavern system that is used by modern visitors is located in a bluff along the Swatara Creek. A second entrance that had been previously used by visitors was sealed for security purposes during the late 1920s. The known portions of the caverns represent the intersection of two passages: the "eastern" cavern and the "northern" cavern, which meet at right angles to form a large space known as the "Indian Ballroom." The geological system in which the caverns are located has been responsible for the creation of multiple sinkholes in an area stretching from Hummelstown to as far as Palmyra, and as far south as Middletown. Temporary closures during flooding In 1972 and 1975, Indian Echo Caverns was closed to tourists temporarily when the Swatara Creek overflowed its banks, filled the cave with water and left behind thick layers of mud when the waters finally receded. The flooding in 1972 was a direct result of Hurricane Agnes. See also Geology of Pennsylvania List of caves List of caves in the United States References External links Indian Echo Caverns Caves of Pennsylvania Limestone caves Show caves in the United States Tourist attractions in Dauphin County, Pennsylvania Landforms of Dauphin County, Pennsylvania