Serpent Mound

The mound runs about four hundred and eleven metres along a bluff, a coiled serpent with a triple-coiled tail and an oval at the head that has been read as an egg, an eye or a swallowed object. It is around a metre high and only reads properly from the observation tower or from above. Dating is disputed: some radiocarbon work points to the Fort Ancient culture around 1070 CE, other samples to the earlier Adena around 300 BCE, and the argument is unresolved. The bluff itself sits on a deformed rock structure now understood as the eroded remains of a meteor impact crater formed 252 to 330 million years ago, which may or may not have influenced the choice of site.

What's there

• A serpent 411 metres long - coiled, with an oval at the head.
• A viewing tower - the shape does not read from ground level.
• A disputed date - Adena or Fort Ancient, the argument is open.
• An impact crater beneath - the bluff sits on deformed rock.

When to go

April to October. Two hours.

Practical notes

From the ground it is a low grass ridge - the tower is essential. There is little else on site beyond a small museum. It is remote, with no public transport. Winter access is limited.

Nearby

The Ohio River is south; Chillicothe's Hopewell earthworks are north-east.

Key facts