RMX Bowser's Castle 1

RMX Bowser's Castle 1 is a race course in Mario Kart Tour. It debuted in the Bowser Tour. Unlike other remix courses, which are based on Super Mario Kart courses, this course is a remix of GBA Bowser's Castle 1 while using the aforementioned course's music. Conveyor Belts act as the main new additions of the course.

This course is a favorite of Fire Rosalina, Penguin Toad, Mario (Aviator), Bowser Jr. (Pirate), Bowser (Santa), Shy Guy (Ninja), Meowser, Pink Shy Guy (Ninja), and the Bronze and Bowser Mii Racing Suits. It can also be a favorite of Chargin' Chuck (Gold) and the Dry Bowser Mii Racing Suit if they reach level 8.