You may be thinking of another waterfall. Wailua is right on the road in Kipahulu. There is no hike other than a trail about 15 yards or so from the bridge...however you can see and photograph the falls without taking the trial. The other waterfall that you may be referring to is Waimoku Falls. That is actually in Haleakala Nat'l Park and is the stream that feeds Oheo Gulch, aka Seven Sacred Pools. That is a highly recommended and publicized hike that is relatively easy. The only strenuous part is maybe the first quarter mile that increases in elevation a bit. The rest is fairly flat, but includes about an overall 650 foot rise in elevation. It's about a 4-5 mile round trip hike and takes about 2.5 to 5 hours depending on how long you take. Take drinking water with you. Be careful. Although it is tempting to take a swim in the relatively shallow pool...3-feet deep maybe..folks have been killed...and nearly killed by falling rocks, such as myself. I moved off of a rock in the pool about 3 minutes before a huge rock fell 400 feet right where I had been sitting. I was out drying off. When it hit, the rock exploded in fragments that rained down on the entire area. It was about 2-feet in diameter. Would have taken me out. There is absolutely no cell service there...and the nearest help is by foot back out the 2+ mile trail to the ranger station. I urge folks to go. It is beautiful and a beautiful hike through the bamboo forest, but be wary that harder things can fall than water...