The Hopewell Ceremonial Earthworks

Between roughly two thousand and sixteen hundred years ago, people of what archaeologists call the Hopewell tradition built enormous geometric earthworks across southern Ohio: perfect circles, squares and octagons of banked earth, some enclosing dozens of hectares, laid out to a shared unit of measurement and connected by long walled avenues. The Octagon Earthworks at Newark are aligned to the northernmost and southernmost risings of the moon over its eighteen-and-a-half-year cycle, a level of astronomical observation that took generations to accumulate. Objects found in the mounds came from obsidian in the Rockies to shark teeth from the Gulf and copper from Lake Superior. UNESCO listed eight sites together in 2023, and they are still barely known even within the country.

What you actually see

• The Octagon Earthworks - the lunar-aligned octagon and circle at Newark.
• Mound City - the group of mounds inside a square enclosure at Chillicothe.
• The Great Circle - the vast circular embankment at Newark.
• The trade objects - obsidian, copper and shark teeth from across the continent.

When to go

April to October for comfortable walking; the earthworks are open year-round and are arguably clearest in winter when grass is short and low sun picks out the banks. The Octagon at Newark had restricted access for many years as a golf course, so check current arrangements before travelling.

Honest expectations

These are grass-covered earth banks, and without interpretation they read as gentle mounds in a park; the visitor centre at Mound City and a little reading beforehand are what make the scale and the astronomy land. The sites are spread across southern Ohio and need a car. Access to the Octagon has been contested and arrangements have changed, so verify before going.

Nearby

Chillicothe and Newark are the two clusters; Serpent Mound is an hour southwest of Chillicothe.