The discovery and reconstruction of Woodhenge — the name is borrowed from the famous British monument, though the Cahokia structure predates the British site’s final form and was constructed differently — has been one of the more remarkable findings of Cahokia archaeology.

It demonstrates that the city’s builders had developed sophisticated observational astronomy, that the alignment of the city with celestial phenomena was deliberate and precise, and that time-keeping and calendar management were important enough to justify the construction of a large and carefully engineered monument for the purpose.

The relationship between astronomical observation and agricultural management is one probable explanation for Woodhenge’s importance: knowing precisely when the solstices and equinoxes occurred would have been valuable information for communities whose agricultural success depended on planting and harvesting at the right times.

But the scale and permanence of the structure suggest that its significance went beyond the purely practical.