How did prehistoric farmers and herders, some 4,500 years ago, succeed in transporting massive stones across hills and streams more than 20 miles away from the haunted plain of Salisbury in England? And when they brought the stones to their sacred place, how did they lift 40 tons of dead weight upright?

What compelling motive drove farmers and hunters of late Stone Age Britain to make such an investment in labor and resources? Archaeologist Julian Richards has perhaps the best and broadest sense of those early people. Joined by engineer Mark Whitby and stonemason Roger Hopkins, they moved, raised and capped their own trilithon (two upright stones capped by a third) in a chalk field near Stonehenge, using hundreds of local volunteers straining on ropes, employing the simple tools used by early Britons. They didn't prove that this was how the magnificent stone structure of Stonehenge was built; they only showed that it was possible to do it in this way.

On May 5, Archaeologist Julian Richards responded to questions during a live event, and to additional questions e-mailed to this Web site for one week thereafter. Check out the archived questions and answers.