Hoopii Falls (or Ho'opi'i Falls) is actually a series of two waterfalls near downtown Kapa'a. The falls are on state land, but the trailhead to the falls is unsigned and not easy to find. Since it resides in a residential neighborhood full of "No Trespassing" signs and guard dogs, we'll leave it up to you to decide if you want to see the falls. Just realize that the residents of the area aren't particularly welcoming to visitors here though I don't really blame them since it could easily attract unwanted traffic and noise if this was a full blown tourist attraction.