Spiral petroglyphs

Why does the spiral appear on rock in places that never met?

Spirals pecked and carved into rock in South America, Ireland and North America, with how each is dated.

Sites in this collection

Spiral Petroglyphs of Güizhagüiña (Guizhaguiña), Ecuador Guizhaguiña, El Oro, Ecuador
Spiral Petroglyphs of Quebrada Seca (Monagas) San Félix, Monagas, Venezuela
Newgrange (Sí an Bhrú) Brú na Bóinne · Ireland
Ingá Stone (Pedra do Ingá / Itacoatiaras do Rio Ingá) Ingá, Paraíba, Brazil
Signal Hill Petroglyph Site Tucson, Arizona, United States