Archaeologists surveying the land around Stonehenge have made a discovery that could change the way we think about our neolithic ancestors: a circle of deep shafts spanning 1.2 miles in diameter around Durrington Walls. Hannah Devlin speaks to Prof Vincent Gaffney about how he and his team made this incredible discovery and why the latest find is so remarkable. Help support our independent journalism at theguardian.com/sciencepod