Today I was flying over the site where a 100 year old factory was recently torn down. I was recording and watching my iPad when I looked up and saw a plane flying over the same site that I was flying. He was a little higher than me but not by that much. Then I realized there was no engine noise from the plane. First time I've ever seen a glider flying over our city. I quickly reduced altitude. Wish I would have gone a little higher to get a photo or video of that thing.