Walking along some hills east of Ensenada, Mexico with friends we saw three metalic balls at the top of a hill. At first we thought they were sculptures on the hill, but they looked as though they were vibrating and shaking. When we got to the top of the hill, these balls were no longer there. I'm pretty sure they couldn't have just been moved, as they looked pretty big (like the size of a car), and the only way down the hill was the route we walked up.((NUFORC Note: Witness elects to remain totally anonymous; provides no contact information. PD))