There is great sthe Reventazone, but like others said the river is dirty and dying from an illplanned damn. (Similar problems will happen to the Pacuare if they decide to follow through with their plans so be sure to sign a petition when you are down there.) The old Peralta section of class five hardley rins anymore because of the damn, but Pascua does and it is fun big water class four. If I remember right always take the left channel. In one instance about 2 or 3 miles into the Pascua section going to the right leads to some very destructive holes. I was in town for a while and the gringo opps took me down for next to nothing whenever I wanted so long as I'd pick up swimmers that fell out of rafts, so you might want to check them out.