Circuit Break Island

Circut Break Island is an island Luigi visits to retreive the third Marvelous Compass piece on his journey to rescue Princess Éclair. The residents of the island have kart races almost everyday, and the winner becomes king or queen of the island for twenty-four hours. However, these races are brutal. The karts race at high speeds are are equipped with missile launchers. It has never been seen, however Luigi mentions it in Paper Mario: The Thousand Year Door.