One of the few effigy mounds in Ohio, Serpent Mound is the largest and finest serpent effigy in the United States. Nearly a quarter of a mile long, Serpent Mound apparently represents an uncoiling serpent. Serpent Mound lies on a plateau overlooking the valley of Brush Creek. Nearby conical mounds contained burials and implements characteristic of the prehistoric Adena people (800 BC-AD 100).

Many questions surround the meaning of Serpent Mound, but there is little doubt it symbolized some religious or mythical principle for its builders. The museum contains exhibits on the mound and the geology of the surrounding area.

Serpent Mound Historical Site is a prehistoric Native American mound located in Adams County, Ohio. Here is a brief history of the site:

1. Construction: Serpent Mound was likely constructed by the Adena culture, one of the earliest prehistoric cultures in the Ohio Valley, around 1000 BCE. It is estimated that the mound was created over a period of several hundred years.

2. Shape and Structure: The Serpent Mound is a massive effigy mound, representing a snake. It stretches for over 1,300 feet (400 meters) and varies in height from around 1 to 3 feet. The mouth of the serpent opens onto a prominent oval-shaped mound, which is believed to have religious or ceremonial significance.

3. Indigenous People: The Adena people were eventually succeeded by the Fort Ancient culture, who continued to use the site for ceremonial purposes. It is generally believed that Serpent Mound was created and used as a sacred site for generations of Native American peoples.

4. Early Discoveries: Serpent Mound was first documented by Europeans in the late 18th century. In 1846, it gained significant attention when the American Ephraim Squier and Edwin Davis surveyed and published a detailed account of the site.

5. Preservation and Recognition: During the late 19th century, initial efforts were made to preserve and protect Serpent Mound. In 1900, the site was purchased by three local Adams County women to prevent its destruction. In 1919, Serpent Mound became one of the first archaeological sites in the United States to be preserved as a state park. It was designated a National Historic Landmark in 1964.

6. Interpretation and Research: Over the years, the Serpent Mound has been subject to various interpretations. Some theories suggest that it was an astronomical calendar, representing celestial events. Others propose that it relates to religious beliefs or marks geographic or spiritual boundaries. Modern research continues to explore these different perspectives.

Today, Serpent Mound Historical Site is open to the public. Visitors can explore the site, visit the museum, and learn about the rich history and cultural significance of this ancient earthwork.