The largest serpent effigy on Earth undulates along a plateau above Ohio Brush Creek. The snake's open jaws clasp an oval enclosure; its tail winds into a triple coil. It contains no burials and no artifacts — it is pure image. The ridge itself lies within an ancient meteorite impact structure, a fact its builders could not have known. Or could they? The ground beneath is geologically strange: faulted, folded, magnetically anomalous.
See Serpent Mound on the globe
Opens with the Sky Alignments lens on, so you can see what it connects to.
Notable facts
- The serpent's head aligns to the summer solstice sunset; the coils may track lunar standstills.
- It sits within a roughly 300-million-year-old impact crater with genuine gravity and magnetic anomalies.
- Attribution is contested between the Adena (~300 BCE) and Fort Ancient (~1070 CE) cultures.
Through the theories
How each theory reads Serpent Mound. Follow a theory to see its verdict and every other site it claims.
Sky AlignmentsEstablished science
Head-to-solstice alignment is measured and real; the egg may be the sun being swallowed.
Ley LinesMostly chance
A favourite of 'earth energy' dowsers, who link the effigy's placement to the crater's magnetic anomalies.
Earth GridNo measurable evidence
The genuine geomagnetic weirdness beneath it makes it the best North American case for 'the ancients sensed anomalies' arguments.
AstronautsNo physical evidence
An effigy fully legible only from the air, coiled over a genuine magnetic anomaly — enthusiasts call it a marker; archaeologists, a procession path.
