Days are getting longer and temperatures are climbing, but summer doesn’t officially arrive until the solstice. The summer solstice is marked on our calendar between June 20-22 annually. But the ancient people who once inhabited the Angel Mounds State Historic Site had a different method for tracking the longest day of the year, along with other milestones in the cycle of the seasons. They used the mounds themselves.
Constructed from 1100-1450 A.D. by people of the Mississippian culture, the 11 earthworks at Angel Mounds were purposefully built to align with certain celestial events, including the summer and winter solstices. Designed by the astronomers of their day, these complex alignments helped the people mark the passing of the year, know when to plant and when to hold ceremonies. The alignments also highlight the cosmology of the people and their relationship with the cosmos.
Indiana University researchers Dr. Edward Herrmann and Dr. William Romain started observing and studying the alignments around a decade ago, underscoring the site’s significance as one of the best-preserved, pre-contact Native American sites in North America. The research also helped our staff members reveal a unique story about Angel Mounds that had been lost to time.
Now centuries later, our visitors have the opportunity to experience the same celestial phenomena that was once observed by the original inhabitants of Angel Mounds. In just a few weeks, the site will host its annual Summer Solstice Alignment event — one of the many wonderful programs the site hosts throughout the year. Visitors will begin arriving before dawn to ensure they are in position to witness the breathtaking views as the sun rises in perfect alignment with mounds A and F.
Again for the Winter Solstice Alignment event, visitors stay late in the evening to see the golden sun as it appears to set into the conical offset of Mound A. These events have recently earned Angel Mounds recognition as one of the best places in the world to see the solstices. Southwest Region Director and Angel Mounds Site Manager Mike Linderman June 2026 added the solstice alignment events to the site’s schedule of programs three years ago.
Fifty people attended that first Summer Solstice Alignment event, and the crowds have grown every year since as more and more people look forward to creating connections to the deep meaning behind these occurrences. “The site comes alive during these events,” he said. “It’s not something we’ve recreated, it’s something that was left to us by the original inhabitants. A system that was created 1,000 years ago is still relevant today, and it’s something the people who originally lived at the site designed that our visitors can still experience firsthand.”
