The Shroud of Turin, housed in a Cathedral in Turin, Italy, houses a relic, known from at least the 13th Century, as the burial shroud (cloth) of Jesus.  It is a sheet of rectangular linen about 14 1/2 feet by 1 1/2 feet, on one side the negative (as with a photographic image, dark is light and light is dark) image of the nude front of an adult man, about 5 feet 8 inches to 6 feet 1 inches tall. On the other side is the nude back of the same adult man.  Injuries are consistent with those of Jesus of Nazareth when crucified.  Carbon dating approximates the linen from about 1240 to 1360 AD, but due to contamination and handing, should be considered inconclusive.  Query:  How could anyone, before the invention of photography in the 1800s, produce what is in effect a photographic negative on a linen cloth?  No one knows the answer to that question.