My family had a great time here! We climbed through the halls of horror and about half way up the rocks. The rocks have a nice grip to them so it’s relatively easy to get at least halfway. The weather was really nice (it’s December) and it was beeezy/windy.
First got here around 3pm, but there was absolutely no space to park - the lot is small, and there isn't any space on the roadside for a while on either side. Came back around sunset and was able to get a spot. If you're not rock climbing, there isn't much to do here. Just walked around for a half mile. Easy trail.
Hard to find, we ended up going to a different but similar tunnel in the immediate surrounding area. Nonetheless we had a lot fun scrambling up and down the boulders and tight areas. Be careful with young kids as it’s harder for them to reach, better to do it in groups for first timers as it’s easy to get lost as well.