I absolutely LOVED this hike.  It's a rough and tumble hike that takes you to three beautiful waterfalls and extremely close to the rim of a Ka'au crater.  There was a lot of rope climbing in which you have to traverse up the mountain right next to the waterfalls.  When you're done though you're standing on a ledge right where the waterfalls begins.  So terrifying and exciting at the same time!  I never heard of Ka'au crater before, but I'm not surprised because it's so hidden deep within Palolo Valley.  It's so lush and green.  It's nice to see land that hasn't been tainted by commercial development.  I felt like I was in the middle of Africa and half expected to see some gazelles prancing through the grass or giraffes grazing on tree leaves.  I hope this hidden beauty stays mysterious forever.