The 12-foot-wide vertical wind tunnel at Niagara Freefall Indoor Skydiving & Interactive Center stretches 20 feet to the ceiling. Inside, it churns with currents of recirculating air—a system that allows its operators to control the wind conditions and temperature regardless of outside weather. Padded walls and floors, as well as trained instructors, keep those inside safe as they're borne aloft by currents of up to 120 miles per hour. Instructors prepare adventurers—who may be as young as 7 years old—for these turbulent conditions during preflight training sessions, during which they divulge flight physics, safety, and communication hand signals. They also encase their visitors in all necessary safety gear, such as helmets, pads, flight suits, and invisible force fields.