professor emeritus of physics at the University of Oregon visited the Oregon Vortex in 1966 and was convinced it was some sort of optical illusion. Owner Maria Cooper agreed with Donnelly that what people are seeing inside the House of Mystery is an optical illusion but insisted something else was happening outside the house that makes people's height appear to grow and shrink depending on their location. Oregon Vortex is also famous for "height change" as the apparent relative height of two people varies, depending on where each stands. The explanation of the strange phenomena is that they are caused by optical illusions. Distorted backgrounds that induce a forced perspective, as with an Ames room. The Oregon site also exhibits phenomena similar to those perceived by visitors at the mystery spot located outside St. Ignace in the upper peninsula of Michigan. In popular culture The site was investigated on a second season episode of the SyFy reality show Fact or Faked: Paranormal Files, and although there seemed to be a small debate between the show's investigators over the "height change" phenomenon, they ultimately concluded that overall, all of the effects demonstrated were optical illusions. The Oregon Vortex was featured in a 1999 episode of X-Files. The attraction is the inspiration for the Mystery Shack, a tourist trap and the main setting for the Disney Channel (later Disney XD) original series Gravity Falls. References External links Oregon Vortex, Official website SyFy Channel - Fact Or Faked: Paranormal Files Oregonians for Science and Reason - Investigation (with pictures illustrating illusions and an animated Ponzo demonstration) New York Times Travel Section Article Dark Destinations - The Oregon Vortex Buildings and structures in Jackson County, Oregon Gravity hills Paranormal places in the United States Roadside attractions in Oregon Tourist attractions in Jackson County, Oregon