Exploring Ohio’s First World Heritage Site in Warren County

Blog by Stacha Yundt

The Grand Canyon, the Great Barrier Reef, the Taj Mahal, Machu Picchu and more. Apart from ranking among our world's most amazing wonders, all of these global icons share something else in common: they’ve all been inscribed as World Heritage Sites by UNESCO (the United Nations Educational, Scientific and Cultural Organization).

In the early morning hours of September 19, 2023, an incredible Warren County wonder joined their ranks.

Oregonia's Fort Ancient Earthworks & Nature Preserve and seven other Ohio sites that together make up the Hopewell Ceremonial Earthworks officially became Ohio's first ever World Heritage site two years ago. They are one of only 26 sites in the entire United States to have earned that exciting, historic designation.

What Is World Heritage?

UNESCO’s World Heritage designation is reserved for places of extraordinary cultural or natural significance. Fewer than 1,300 sites worldwide carry the title, and just 26 in the United States. Earning this recognition is the culmination of decades of collaboration, research, and advocacy by the Ohio History Connection in partnership with tribal nations with ancestral ties to the earthworks.

The Hopewell Ceremonial Earthworks

The Hopewell Ceremonial Earthworks are a collection of 8 sites throughout Ohio that are remnants of the Hopewell Period. These amazing earthen mounds were created 2,000 years ago by early American Indians and serve as a testament to their understanding of geometry, architecture, astronomy and more. Some of the walls at these earthworks reach over 30 feet in height.

Many of the sites are geometric enclosures, built into perfect circles, squares, and octagons across hundreds of acres and a number of them were constructed with clear lunar and solar alignments in mind. Despite the fact that many of these earthworks have “Fort” in their names, they were not protective or combat-related sites, but rather places of great ceremonial importance to the early American Indians who built them.

Fort Ancient Earthworks in Oregonia

While the Hopewell Ceremonial Earthworks appear in numerous regions across Ohio, one of the most prominent is right here in Warren County.

Unlike the geometric earthworks in Newark and Chillicothe, Fort Ancient Earthworks in Oregonia is a massive hilltop enclosure — so large that you could fit the entire Great Pyramid of Giza inside! It’s the largest hilltop enclosure in North America and was Ohio’s first State Park before becoming a part of the Ohio History Connection. While parts of the earthworks were damaged or even destroyed by farming over the years, Fort Ancient’s earthworks remain some of the best preserved in the world because of their hilltop location. Today, Fort Ancient is also a nature preserve and boasts an impressive museum that follows Ohio’s first peoples from the Ice Age all the way up to post-contact with European settlers.

A Road Trip Through History

While Fort Ancient is the only World Heritage site in Warren County, it's part of a much larger cultural landscape. The rest of the earthworks that make up the Hopewell Ceremonial Earthworks are located just a short road trip away in Ross and Licking Counties.

In January 2025, the Octagon in Newark, one of the most remarkable of these, fully reopened to the public for the first time in more than a century. Known for its precise alignments with the lunar cycle, the Octagon now welcomes visitors year-round, creating new opportunities to experience the legacy of the incredible architects firsthand.

Preserving and Experiencing the Legacy

World Heritage inscription is not simply a recognition of the past, but also a commitment to the future. By preserving these earthworks, Ohio honors the knowledge and artistry of their Indigenous builders while ensuring that generations to come can continue to learn from and be inspired by them.

Whether you begin your journey at Fort Ancient or venture farther to explore the full network of Hopewell Ceremonial Earthworks, a visit offers more than a lesson in history. It offers a chance to stand in spaces of enduring significance and reflect on the ways humanity has always sought to connect with the earth, the sky, and one another.