There were only 2 roller coasters ever built like CHAOS. Opryland's version opened on March 25, 1989 with a 40-car train (which is still a world's record). A few month's later, it's twin, named the Revolution, opened with a 30-car train in Bobbejaanland, a theme park in Antwerp, Belgium. Like CHAOS, the Revolution has gone through several different themes. This year, the park introduced virtual reality to the attraction and renamed it Mount Mara. Riders wear Samsung headsets and experience a true 3D experience (unlike the light diffraction glasses used on CHAOS that everyone called 3D!). Those that choose not to wear the Samsung headsets can still enjoy 1/2 of the original clock projection that CHAOS used for its first few years.