Diamond City Stadium is a major location in WarioWare Gold. It is a stadium in Diamond City where Wario hosts his Wario Bowl tournament. It is the setting for all of Wario's tutorial stages and cutscenes, as well as the setting for Wario Deluxe's story in the Ultra League.
Diamond City Stadium first appears in Wario's first cutscene, where he announces the official start of his Wario Bowl to a cheering crowd, and explains that there are 3 different leagues, with 3 different sets of controls. Suddenly, Lulu appears and threatens Wario. Wario dismisses this and starts the first league just as Lulu runs off.
Diamond City Stadium next appears in one of Wario's cutscenes, where he is shown bathing in a tub full of coins he collected from the tournament fee, which he brags about. He praises the Pot of Luxeville but notices an odd odor, which he identifies as the scent of victory.
In Wario's next cutscene, he is still at Diamond City Stadium, and is shown just waking up. Realizing that the player has already completely eight stages, he naps in anger.