If not for Rainbow Road, Bowser Castle would probably be the most famous track in the Mario Kart series. Like Rainbow Road, some version of Bowser Castle has always been a track in every Mario Kart. In Super Mario Kart there were 3 versions and Mario Kart: Super Circuit actually has 4 versions of the track. Lava and Thwomps have been involved in almost every Bowser Castle course as it is regarded by many as one of the most dangerous courses in every Mario Kart game. It has also been known to be under the name of Bowser's Castle in some Mario Kart games.