Holy heck! This was hands down one of the most fun, amazing, interesting, funky, enjoyable experiences of my life. I had no idea what we were getting into, I figured your basic here's a cave, don't touch anything, wooo let's turn off the lights, here's some scratches on the wall kind of tour. It was anything but. It was far more physical than I anticipated (in a good way), far longer than I expected (also in a good way) and truly ranks in the top 5 of things I've done in life so far. Wear REAL shoes, like sneakers, and REAL socks. Dress sparingly, just a tank top or tshirt and shorts is all you will want to deal with. (we went in mid December, still plenty HOT). Something quick dry is nice, but you won't really have a chance to dry off, and too much clothing might get chilly sticking to you. Bring a full on towel/change of clothes, change of shoes, fresh undies, fresh bra, and EAT A GOOD, HEARTY BREAKFAST before you go.