Luray Caverns has a reflecting pool, appearing to double the number of formations
Source: David Jones, Reflecting cavern lake
In Virginia, Luray Caverns is the commercial cave with the greatest number of speleothems - stalactites, stalagmites, and other formations.
It also has the largest musical instrument in the world, the "Great Stalacpipe Organ." Today, organists use a keyboard to trigger hammers to vibrate stalactites that resonate at different frequencies. Electronic mallets are wired throughout the caverns and connected to a keyboard. When the organist depresses a key, a rubber-tipped plunger strikes a stalactite that creates a tone. As the organist combines notes, visitors deep underground hear classics and other tunes such as "Shenandoah."
Leland Sprinkle, the inventor, conceived the idea after visiting the cave with his five-year old son in 1954. He saw a tour guide use a rubber mallet to tap cave formations and make sounds. He began his initiative by finding different stalactites throughout Luray Caverns that could serve as the equivalent of individual organ pipes:1
soon after discovery, people began tapping out tunes on a stalactite formation in Luray Caverns known as the Organ
Source: Norfolk and Western Railroad, The Caverns of Luray (p.36)
Rev. Horace Hovey mapped Luray Caverns and defined names of many formations
Source: Internet Archive, The Luray Cave (by S. J. Ammen, 1882)
early cave guides joked that a formation that appeared to be fish drying on a rack was made of "rockfish"
Source: Norfolk and Western Railroad, The Caverns of Luray (p.22)
Luray Caverns has attracted tourists since its discovery in 1878
Source: Library of Congress, Virginia - grandest of American caverns - scene in the ballroom in the newly-discovered cave at Luray, Page County, December 27th, 1878