[Thanks to Evan]Waterfall swing. How did things work before computerization?
Water recirculates through 273 independently controlled solenoid valves at the top of the structure to create a wall of water. This water starts from a collection pool on the ground and is pumped up to a large pipe that feeds the solenoids. Sensors mounted on the swingset gather information about the angle and speed of each swing. That information is sent to a computer that predicts the action of the rider. The computer then creates a hole in the wall of water, allowing the rider to swing through without getting wet.