Silver Dollar City, MO, USA.
On May 17th, Silver Dollar City's White Water Park will be home to their largest water slide. Standing tall at four stories high will be KaPau Plummet!
Riders will stand on a trapdoor that opens into an enclosed 70º, free fall plunge at 26 feet per second (that's a top speed of 17.7 mph/28.5 kph). Half way down the 240 ft (73 mtrs) long slide, it will curve and lead into a pool. There will be two identical slides offering the chance of a splashtastic duel.
Silver Dollar City's website.