What astronomical event might the Great Serpent Mound be associated?

The Great Serpent Mound is often associated with astronomical events related to the lunar and solar cycles. Specifically, it is believed to align with the summer solstice and the lunar standstill, which occurs every 18.6 years. The mound's construction and design may have served as a ceremonial site for observing these significant celestial events, reflecting the ancient cultures' understanding of astronomy and their connection to the natural world.