Airs Wednesdays at 10/9c on HISTORY. To this day no one knows the true purpose of Stonehenge, the ancient monument in the British countryside. There are many theories: a shrine celebrating a god; an ancient solar calendar; or maybe a sacrificial altar for an unknown pagan religion. MysteryQuest travels to the ancient ruin with a new theory--that ancient people may have used the sound reverberations inside this circle to induce a trance-like state among participants in ancient rituals. Were there bizarre rituals, even sacrifices, to some long-forgotten god? The team will attempt to find evidence that could crack open this persistent mystery. Visit the official HISTORY Facebook Fanpage at http://facebook.com/History, Follow us on Twitter at http://twitter.com/History_Daily