On my last full day, I got to do the Manoa Falls hike I was so excited about.
Transportation and the tour were included with the pass and though my mom had planned to hike with me, I ended up doing the hike alone. There was one other girl who was on the hike but she freaked out about halfway up and decided not to finish the trail.
I'm terrified of heights and this hike was completely different from Diamond Head. For one, it gets slippery. Two, there are no rails. Three, there are trees and a steep cliff drop. I got really lucky because that day was considerably drier than other days and everything was a bit easier. Still, it was a bit freaky hiking up the side of a cliff sort of alone. There were other people along the way on their way up or down, so it wasn't like I was completely by myself. About 3/4 of the way up, someone actually broke their ankle and had to be air lifted out by helicopter since there's really nowhere for an ambulance to go (I really hope she has good insurance). The slightly scary trek was definitely worth it because the falls at the top are beautiful and the jungle is really really pretty (they filmed parts of it for the arena Catching Fire).