Luray Caverns

Deep in Luray Caverns, rubber-tipped mallets tap ancient stalactites to play music, an instrument built from the cave itself. The Great Stalacpipe Organ, designed in 1956 by Leland W. Sprinkle, spreads its solenoid-driven strikers across about 3.5 acres of chambers and is often called the world's largest musical instrument. The caverns lie just west of Luray, Virginia, in the Shenandoah Valley, where groundwater dissolving limestone over millions of years opened rooms more than 10 stories high and decorated them with columns, flowstone and draperies.

Five local men, including Andrew Campbell and Benton Stebbins, discovered the caverns on August 13, 1878, after noticing cool air flowing from a sinkhole. Tours began that same year, and today about half a million people a year walk the 1.5-mile (2.4 km) paved route. Highlights include Dream Lake, a pool only about 20 inches deep whose still surface mirrors the stalactites so perfectly they seem to rise from below. The caverns were designated a National Natural Landmark in 1974.

• Virginia
  The Old Dominion, from the Chesapeake to the Blue Ridge located in
• Shenandoah National Park
  A long ribbon of the Blue Ridge in Virginia near
• Skyline Drive
  The ridgetop road through Shenandoah near
• The Appalachian Mountains
  The ancient, worn mountains of the eastern U.S. part of
• Howe Caverns
  Upstate New York show cave with an underground boat ride related
• Ruby Falls
  An underground waterfall deep inside Lookout Mountain, Chattanooga related