UFOs have been seen over our skies for millennia, and their depiction in man-maid art can be seen even since we were painting on cave walls. UFO sightings remain among the biggest mysteries of our times, with no concrete evidence about their real nature. Some UFO cases are so bizarre that seem to defy our knowledge of the physical world, and by uncovering the truth behind them we could expand our knowledge of the universe.In this book, you will find the most famous UFO cases of modern history that have not yet been, beyond any doubt, identified."With no apparent change of weather, but all on a sudden, the sky burst asunder, and a huge, flame-like body was seen to fall between the armies. In shape, it was almost like a wine-jar, and in color, like molten silver. Both sides were astonished at the sight, and separated. This marvel as they say, occurred in Phrygia, at a place called Otryae"-Plutarch, 74 B.C.