This antler pick was found in the packing of Stonehole E, near the entrance to Stonehenge. It was sampled in 1995 as part of a pioneering programme of radiocarbon dating, which showed that it was shed between 2490 and 2200 BC. Stonehenge has been at the forefront of developments in radiocarbon dating, with a sample of charcoal from Aubrey Hole 32 sent to Professor William Libby in Chicago in 1952. Libby had developed the method of dating by measuring the decay of radiocarbon and this was the first sample dated from a British prehistoric site. The result was between 3020 and 1520 BC. Later, in the 1960s, when radiocarbon results could be calibrated with reference to sequences from tree rings, there would be a revolution in our understanding of the antiquity of prehistoric monuments, with existing date estimates pushed back to a millennium earlier. Today, we have nearly 70 radiocarbon dates from Stonehenge alone and our understanding of the date of prehistoric sites in the World Heritage Site is more detailed than ever before. Caption: Susan Greaney (English Heritage)