All over the country there are Gravity Hills (also call Mystery Spots, Magnetic Hills etc) where things appear to roll up hill. Even in our own area as you can see in the Haunted Los Angeles webpage. You can find more on the 10 Magnetic Hills page. But what is going on here? Can gravity really work differently in different places?
Have your students explore gravity hills and test them with the Gravity Hill Lesson. Explore the laws of motion and the psychology of optical illusions.