LURAY, Va. (WDVM) — Nestled in the Shenandoah Valley is Luray, Virginia. It’s known not only for its its sweeping mountains and rambling rivers but also for a natural beauty you can only see by going underground. Luray Caverns are the largest caverns in Eastern America and one of the largest caverns in the world.

The caverns cover 64 acres and are 260 feet underground. It’s a tourist destination that brings in thousands of visitors every year going underground to see a 400 million-year-old natural marvel.

“Luray Caverns was discovered in August of 1878. Almost immediately after that tours began to be conducted in this natural wonder we opened on November the 7th 1878 and have been open for over 140 years,” said John Shaffer, Director of Public Relations at Luray Caverns.

Inside the caverns are hundreds of formations called stalactites and stalagmites.

“Stalactites are the formations that grow down from the ceiling…stalagmites grow from the ground up,” Shaffer said.

Inside its Cathedral Room, the caverns also house the largest musical instrument in the world known as the Great Stalacpipe Organ.

“Well the organ is unique because it uses stalactites as its tone sources and they cover over 3 and a half acres,” said Larry Moyer Maintenance Engineer of The Great Stalacpipe Organ.

Work to construct the instrument began in 1954. The instrument was first played in 1957.

“Leland Sprinkle invented the organ. He came through the caverns on a tour with his son and they used to play a song on what we call the old pipe organ by just gently tapping some stalactites and he got the idea why couldn’t I build an organ that would play music for all the people that came through,” said Moyer.

The caverns are open year-round, are step-free, and are always a comfortable 54 degrees in the summer, spring, fall and winter. While you’re visiting Luray Caverns, you can also check out some of the above-ground features like Toy Town Junction, Rope Adventure Park, the Garden Maze, the Car and Carriage Caravan Museum, and Shenandoah Heritage Village.