WILTSHIRE, ENGLAND—Dry spots in the grass that appeared during last year’s summer drought suggest that the outer circle of sarsen stones at Stonehenge was once complete. “I was standing on the public path looking at the grass near the stones and thinking that we needed to find a longer hosepipe to get the parched patches to green up," Tim Daw, who cares for the site, told BBC News. "[There was a] sudden light bulb moment in my head, and I remembered that the marks were where archaeologists had looked without success for signs that there had been stone holes, and that parch marks can signify them.” Archaeologists had conducted a high-resolution geophysical survey few years ago that failed to find evidence of stones that would have completed the circle. “It’s great that people who know the site really well and look at it every day were able to spot these parch marks and recognize them for what they were….If we’d had a longer hosepipe we might not have been able to see them,” added Susan Greaney of English Heritage. To read about the suprising similarities between Stonehenge and monuments in Madagascar, see ARCHAEOLOGY's "Conversation: Sacred Stones."