Some of these mini-worlds are found by exploring new paths, others by retracing old ones
Super Mario Bros. Wonder: all secret exits
Super Mario Wonder Hidden Exits: Which Levels Have Secret Flagpoles? - GameRevolution
Super Mario Bros. Wonder: Special World Unlock - All Secret Warp Points
All Super Mario Bros. Wonder Levels With Secret Exits
Super Mario Bros. Wonder Secret Exits · Unlock every Special World level, too
Super Mario Bros. Wonder Flower Coins And Wonder Seeds Guide - Game Informer
Mario Bros. Wonder Special World - How to unlock all levels
ALL 7 Hidden SPECIAL WORLD Entrances ~ Mario Wonder
All Super Mario Bros Wonder Secret Exit Locations
All Special World Entrance Locations In Super Mario Bros. Wonder