In Bacon Hole Cave in South Wales, red horizontal bands have been recognised as a cave painting more than 17,000 years old
In Bacon Hole Cave in South Wales, red horizontal bands have been recognised as a cave painting more than 17,000 years old. They were found as long ago as 1912, but in 1928 they were written off as a natural seepage of iron oxide, and for almost a century the bands passed for an ordinary natural stain. Uranium-thorium analysis, however, has revealed pigment applied with a finger. It turns out that a specimen of Britain's most ancient art has spent a hundred years listed as a defect of the rock