COLLINSVILLE – The moment when day and night are equal is almost here, and Cahokia Mounds State Historic Site plans to welcome it with a special event at the “Woodhenge” solar calendar.

Sun watchers will gather on Sunday, September 24, at 6:30 a.m. to see the dawn sun emerge from the front of Monks Mound a half-mile away, as seen from Woodhenge, a reconstruction of the calendar used when Cahokia Mounds was home to thousands of Native Americans. The huge circle of posts stands about one mile west of the site’s Interpretive Center on Collinsville Road, and a parking lot is available.

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Out of respect for Native American beliefs, no rituals or ceremonies will be held at the free event. But visitors will stand in the same place where the Mississippian people once gathered to watch the sun rise.

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An archaeologist will explain the discovery, form and function of Woodhenge while awaiting the dawn. Cahokia Mounds observes the Equinoxes and Solstices on the Sunday morning closest to the actual event so that more people are able to come observe and learn about the discovery, form and function of this ancient sun calendar. Visitors are welcome to observe the actual Equinox sunrise on Thursday, September 21 if they wish, but there will be no program that day.

Woodhenge is a calendar of posts arranged to line up with sunrises throughout the year, including the Spring and Fall Equinoxes and the Summer and Winter Solstices. Residents of Cahokia Mounds – which was then the largest city north of Mexico and built by the Mississippian culture– considered these days sacred, and built several Woodhenges from AD 1100-1200 to track these events and other dates important in their ceremonial calendar.

Cahokia Mounds State Historic Site, administered by the Illinois Department of Natural Resources, is just eight miles from downtown St. Louis, in Collinsville, Illinois, off Interstates 55/70 (Exit 6) and Interstate 255 (Exit 24), on Collinsville Road. The Interpretive Center is open 9 a.m. - 5 p.m. There is no admission fee but we do suggest donations of $7 for adults, $5 for seniors, $2 for students and $15 for families.

For more information call 618-346-5160 or go to

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