I get a little claustrophobic sometimes and walking down in the small cave tunnel with no end or start in sight kind of freaked me out. There were people close behind me so I didn't feel like I had the option to go back. Plus Bob was going way up ahead with some of the kids and I was getting a little stressed about it. Nothing major, I just pressed on and felt fine when we got to the end and saw the opening. I'd feel more comfortable up on a hight rock or sitting on a ledge then in a tunnel.
We have definitely seen and done a lot here in San Diego and this was ok. I wouldn't really consider it a must do, but it wasn't bad either.