Gravity Falls The show concerns the adventures of 12 year-old twin brother and sister Dipper and Mabel Pines, whose summer plans are ruined when their parents send them off to their Great Uncle Stan in the fictional town of Gravity Falls, Oregon. "Grunkle" Stan lives in and runs The Mystery Shack, a tourist trap which overcharges unlucky visitors for a glimpse at the world's most bizarre museum, but little do Dipper and Mabel know that there really is something very strange going on and they must rely on one another to find their way in this unfamiliar town