Thirteen (officially stylised as TH13TEEN) is a steel roller coaster at Alton Towers in England. The ride was constructed by Intamin and opened on 20 March 2010. It is the world's first vertical freefall drop roller coaster, on which the track and train freefall approximately five metres in darkness. The ride replaced and is built on the former site of the Corkscrew, which resided at Alton Towers for 28 years between 1980 and 2008.