Twisted Colossus is a steel roller coaster at Six Flags Magic Mountain amusement park. Originally designed and built by International Amusement Devices, the roller coaster opened as Colossus on June 29, 1978. It was the tallest and fastest wooden roller coaster in the world and the first with two drops greater than 100ft. Colossus became well known after appearances in film and television, including the box-office hit National Lampoon's Vacation.After more than 36 years in operation, Six Flags announced in 2014 that Colossus would be closed permanently on August 16, 2014. Within two weeks of its closure, Six Flags announced that the roller coaster would reemerge in 2015 as a steel-tracked roller coaster named Twisted Colossus. It was renovated by Rocky Mountain Construction to feature barrel roll inversions, and a near-vertical drop. Twisted Colossus opened on May 23, 2015.HistoryFor its next attraction to debut in 1978, Magic Mountain wanted a wooden roller coaster for the classic "rumble and sway" experience that they felt was missing from steel coasters. They hired Ohio-based International Amusement Devices (IAD), who began designing Colossus in January 1977. IAD in turn subcontracted Bernard Brothers Construction for the construction of the ride, Continental Consultants for all of the mechanical systems, and Lorenz & Williams for the structural engineering and electronic systems. A member of the design team traveled to Mexico City to study Montaña Rusa – the largest wooden roller coaster in the world at the time – in order to help plan for the project.