We had done a cave tour this summer in Ohio. It was very interesting but does not hold a candle to the Inner Space Caves. We spent the night in Round Rock and made the drive to be at the caves when they opened for the first tour. Several people had arrived before us but we were able to secure a spot on the 11:20 tour.
I purchased our tickets with an Entertainment book coupon for a buy one general tour get one free. So we only had to pay $40 for the 3 of us to tour. We milled around the gift shop for about fifteen minutes before gathering for the start of our tour. The rules are pretty basic such as no food or drink in the cave and use the bathroom before you head in.