Linville Caverns is North Carolina's only commercial cave system. It is a relatively small cave; tours only take about 30 minutes.
The drive from Asheville to Linville Caverns took us about an hour and 10 minutes. By the time we got there it was pouring down rain, but since caves don't close for rain, we were in good shape!
I purchased 2 adult and 3 children's tickets in the gift shop (there's always a gift shop!) for $29. Then we tore the kids away from the carved rocks and stuffed animals in the gift shop to get in line for the tour.
Tours start about every 5-10 minutes and include only 15 people per tour. This is nice because you can hear the guide better than on larger tours we've taken. 
The entrance to the cave has a small stream running alongside of it which is full of trout! The kids had a ball watching the blind and half-blind cave fish while we waited our turn to go in.The trout actually led to the modern discovery of the cave as local fishermen explored how the fish were able to swim into what seemed like solid rock.
Our guide was pleasant and informative and walked us through a little of the history of the cave, including an area that was home to Civil War deserters for nearly a year. The only way in at that time was wading through the very chilly stream... they picked a spot others weren't likely to explore. However the smoke from their fire inside the cavern got them caught- locals eventually came out to investigate why the side of Humpback Mountain was smoking! 
The highlight of our tour was something we were told not to expect.. we saw a live bat! The guide had just finished explaining how the cave only has bats in the winter time when one swooped down from the ceiling and narrowly missed her head.
We trooped tightly into a narrow chasm where we walked on iron bars over clear water. As we packed in (it was a dead end) the guide told us we were suspended over a bottomless pit. Divers have submerged in the water down to 90 ft and ropes have measured more than 120 ft but the depth hasn't yet been accurately measured. We were warned not to drop cameras or keys into the pit, for obvious reasons! 
<-I don't remember what this formation was actually called because my daughter called it "the cave pickle" for the rest of the weekend.
The tour was relatively flat and a comfortable walk, with level paths and no stairs or tight squeezes although the taller people (I hear) had to duck here and there. (I don't have that problem, myself!)
It would be a good tour for smaller children or older grandparents, although small children might be frightened by the 30 seconds or so of "total blackness" where all the lights are turned off for the total cave experience.
Don't count on using your GPS to find Linville Caverns- it's unlikely to work! Our TomTom was totally confused. Print out and follow the Linville Caverns Driving Directions from their web site and enjoy the beautiful scenery on your drive. Part 3- Spears BBQ
