This stage is Fire Bros. Hideout #2 (5-B). This complete walkthrough will provide you with a 100% video playthrough. To find the hide out, go to the bottom left of World 5 and tap A at the small circle spot. The easiest way to kill the Fire Bro is to stand on the rising platform, jump on the Fire Bro’s head to take it out along with the entire stack of Goombas.