Tuckaleechee Caverns

"It was pure luck that members of the the National Speleological Society stumbled across the Big Room, an enormous cavern in the middle of the system, a year after reopening. This attraction brought in new tourists after it was added to the mile-long guided tour. The Big Room is more than 400 feet long, 300 feet across, and 150 feet deep, according to Tuckaleechee’s official website. Stalagmites, rock formations that grow from the floor toward the ceiling, reach up to 24 feet in the middle of the Big Room."