It's actually one big cave, pretty cool though. I don't think you can make a day out of it unless you visit Shoshone Ice Caves as well. It is just down the road to the north from Mammoth Cave. I suppose, after going to the museum you can make a day out of it. Not sure of the cost, but if I recall, last time I went it was fairly cheap. Definitely some cool stuff in the museum and the guided tour at Shoshone Ice Caves is good. I walked through Mammoth Cave on my own.