The Vortex Illusion is a rotating tunnel that creates a very strange sensation when you attempt to walk through it. The bridge you walk on is completely stationary and does NOT move yet the illusion created by this effect makes your brain think the bridge is rocking from side to side. Your reflexes cause you to hug the support rails to prevent yourself from falling over. It was featured in London's Shriners Haunted Mansion for many years and proved a most popular attraction.