COLLINSVILLE, Ill. (AP) – Visitors to the Cahokia Mounds State Historic Site in the southern Illinois community of Collinsville will get a glimpse at a sacred moment in the lives of Native Americans who lived there a thousand years ago.

In a news release, officials at the site say on Sunday the dawn of the summer solstice will be observed at “Woodhenge.”

Woodhenge is a calendar of posts arranged in a line with sunrise on the longest day of the year – June 21 – the year’s shortest day in December and the spring and fall equinoxes, when day and night are the same length.

Visitors can stand where Native Americans who once lived in what was the largest city north of Mexico gathered to watch the sun rise above the mound.