do you know of any famous mysteries?such as UFO

Well it is not famous world wide or something but I know of one in my city. There is this house that had all this strange things that happen there. so one day a giant cross was seen on the house (about 10 m by 4) they painted the house so many different colours and the cross still comes up. they had people testing it for so many things and there is still no explenation how and why it comes.

Years ago I worked with a girl whose boyfriend was killed when his car drove into a tree on a country road. Now she was told unofficially by the police in attendance that there was no way his car left the road under normal circumstances, by the tyre marks it was like his car was picked up turned to the right, the policeman said there was no way a car could leave the tracks that were made and he also said there was burn marks in the paddock near bye but they told her it was going to be put doewn just as an accident.