Worth the ~$20/adult entrance fee, but ONLY if you come on a non-vacation weekday
Also, I strongly suggest buying the combination ticket with Rock City and Battles of Chattanooga. Be warned, if you disregard my warning and come to Ruby Falls with the tourist crush you’ll feel like you were ripped off; Firstly, there’s insufficient parking so you might find yourself having to walk a fair distance up a steep hill. Then you’ll enter, only to find you have to wait as long an hour to be able to take the elevator down into the caverns. Once there you’ll be herded quickly like cattle through narrow caverns that aren’t wide enough for more than a single file of humans — with barely a chance to take photos of said caves, and after that, once you get to the room where the falls are, you’ll be forced to stand in line to get your picture taken by the falls, and only allowed about 30 seconds to do it, all for the low low price of about $20/adult. I have this on very good authority from numerous fellow tourists I met who had made that mistake, and were very very unhappy with their experience.
I however, heeding the warnings of my fellow travelers, arrived on a weekday, when there was intermittent rain and no schools were out on vacation. I arrived mid afternoon and parked three spaces away from the main entrance. I bought my ticket, and had to hustle to the bathroom because the next elevator ride down was in five minutes. Once down there I was in a group of maybe 20 people, and while down in the caverns we only had to wait by the side to allow one group to pass us going the other way. When at the falls there was no line to take photos, and instead we could just do it as we wished.
The only bad thing, and it was pretty bad, was that after almost five years of dutiful service and managing to remain in pristine condition that whole time, I made the mistake of asking a Korean tourist, of the variety who used to live in my neighborhood when I taught University in S. Korea (fitting into their groups is such a priority for Koreans that they almost wear uniforms that help you to identify which ‘class’ they belong to), to take a picture of me, and he proceeded to drop my iPhone 4S onto the cave floor smashing the back screen to smithereens
— right after this picture:
On the upside, the iPhone SE was due to be released in a week or two, and I finally had justification for buying a new phone.