Twisted Colossus is a steel roller coaster located at Six Flags Magic Mountain in Valencia, California. Originally designed and built by International Amusement Devices, the roller coaster opened as Colossus, a dual-tracked roller coaster, on June 29, 1978. It was the tallest and fastest wooden roller coaster in the world and the first with two drops greater than 100 feet (30 m). Colossus became well known after appearances in film and television, including the box-office hit National Lampoon's Vacation and the made-for-TV movie Kiss Meets the Phantom of the Park.
After more than 36 years in operation, Six Flags closed Colossus on August 16, 2014. Rocky Mountain Construction renovated the ride converting its wooden track to steel, allowing for the addition of inversions and steep drops. It retained much of its wooden structure, however, and reemerged as Twisted Colossus on May 23, 2015.