Not only is this the largest cavern in the state, it also features the world's only "stalacpipe organ," composed of stalactites (calcite formations hanging from the ceilings of the caverns) that have been tuned to concert pitch and are tapped to create echoing sound. The organ is played electronically for every tour and may be played manually on special occasions. A one-hour tour begins every 20 minutes. Beyond the organ, Luray Caverns holds plenty of natural beauty, like the Dream Lake that perfectly mirrors back the stalactite formations. It's an easy addition to Skyline Drive, just 9 mi west on U.S. 211.