LONDON, ENGLAND—While digging a Neolithic temple complex some 15 miles from Stonehenge, archaeologists led by Kingston University's Helen Wickstead discovered a massive sand and clay sinkhole that could hold 6,000-year-old plant material. The site, known as Damerham, sits on chalk land, so the discovery of sand and clay, which preserve plant life better than chalk, was unexpected. "We don't often find materials like this that capture and preserve the plant remains-pollen or phytoliths-from a specific time period," said Wickstead in a statement. "We are very hopeful that, within this material, there will be evidence of plant life that will help us continue to piece together the puzzle of human habitation on this significant site."