A pool is a great addition to any backyard, but it’s not a very imaginative way to keep cool on those long summer days. Maybe your pool features a topsy-turvy slide, a built-in hot tub, a decorative waterfall, or even a grotto, but these features and addons are becoming more commonplace nowadays, and won’t separate your backyard from the thousands of pool-filled yards in your town. If you truly want your backyard to stand out (and you have a few old bathtubs that you’d like to upcycle) consider building a unique three-story, three-tub waterpark experience. In a recent video, YouTuber colinfurze brings his son's invention, a bunk bath, to life.