Whitewater rafting is a sport and a recreational activity. With rafting you have to go through the course of rivers in the direction of the current (downstream), on any type of boat or raft. Those whitewater rivers have some degree of turbulence, that is why they have the name 'whitewater rivers', because of the color of the foam which appears when the river is turbulence.
It is possible to go rafting with Valencia Adventure in Cabriel River, Mijares River and Turia River