Kingda Ka is a roller coaster located at Six Flags Great Adventure in New Jersey, USA (United States). It is the tallest (List of roller coaster records#Height records) and fastest (List of roller coaster records#Speed records) roller coaster in the world, claiming the titles from Top Thrill Dragster at Cedar Point when it opened on May 21, 2005. The train is launched by a hydraulic launch mechanism (Accelerator Coaster#How it works) to 128 miles per hour (206 km/h) in 3.5 seconds.cite web url= title= Kingda Ka: Great Adventure publisher=Six Flags accessdate=2007-08-22 At the end of the launch track, the train climbs the main top hat (Roller coaster elements#Top hat) tower, reaching a height of 456 feet (139 meters).