America's Stonehenge, erected approximately 4,000 years ago, is one of the largest and possibly oldest megalithic (stone-constructed) sites in North America. Like Stonehenge in England, America's Stonehenge was built by ancient people well versed in astronomy and stone construction. It has been determined that the site is an accurate astronomically aligned calendar. It was and still can be used to determine specific solar and lunar events of the year. The self guided tour of America's Stonehenge takes roughly 1 hour. The trail is 1/2 mile roundtrip.