A Stone With Two Different Carvings Turns Up at a Galician Hillfort

A granite stone about 30 centimeters across has surfaced at an Iron Age hillfort in northwestern Spain, and it carries a different carving on each face. One side shows a carefully made triskele, a symbol of three curved arms spiraling from a central point. The other side holds a rougher petroglyph that archaeologists have not yet explained.

The site: Castro do Pico da Bandeira

The stone comes from Castro do Pico da Bandeira, a hillfort near A Guarda in Galicia. It sits on Mount Torroso, in the Salcidos area. Castros like this one are fortified settlements built by the Iron Age communities of northwestern Iberia, and Galicia has hundreds of them. The current excavation campaign is promoted by the Salcidos communal landowners’ association, and the work is directed by archaeologist Nerea Vilariño of Árbore Arqueoloxía e Restauración.

The team is digging a large circular building. According to Arkeonews, people used it between the 1st century BC and the 1st century AD, roughly from 100 BC to AD 100. More than half of the structure remains unexcavated, so the full picture is still to come.

What the team found

The triskele has three curved arms that run counterclockwise from a central point. Arkeonews describes it as carefully carved, and the stone lay protected under collapsed rubble. Turn the stone over and the style changes. The petroglyph on the reverse is rougher and less refined, and its design and meaning are still under investigation.

Published reports give slightly different measurements, but all of them put the stone at roughly 30 centimeters across. Other finds from the building include possible entrance slabs, architectural fittings, pottery fragments, Roman amphora fragments whose origin is not yet established, and stone objects called amarradoiros made of orthogneiss, whose purpose is also uncertain.

Why two carvings on one stone is puzzling

The triskele is a well-known motif in the Celtic-speaking and Atlantic world of the Iron Age, but a stone that pairs a polished-looking triskele with a cruder petroglyph on its back is unusual. Archaeologist Benito Vilas noted that the engraving drew attention from the start. He suggested a possible comparison with an engraved stone with a reverse petroglyph from an Iron Age bathing complex at Briteiros, in northern Portugal. That is a lead to follow, not a match that anyone has confirmed.

The bigger question is timing. Someone may have carved both faces in one sitting. Alternatively, one carving may be older, and a later person may have reused the stone and added the second design. Nobody can say yet, because the carvings themselves have not been securely dated. The building’s occupation dates the context, but a stone can be older or newer than the walls around it.

What a circular building might tell us

Round houses are common in Galician castros, so the shape alone does not make this structure special. Its large size, the possible entrance slabs and the imported Roman pottery fragments hint that the household may have had some standing, though that remains an interpretation and the team has not tied the stone to any particular function. Because most of the building is still buried, later seasons could change the story.

Caveats and open questions

Most of what we know comes from a news report that draws on the excavating group’s own announcement. We could not locate a formal publication or peer-reviewed study, and the article does not include direct quotes from the researchers. Questions that remain open include the age of each carving, whether the same hands made both, what the symbols meant to the people who made them, and whether the stone had a ritual, decorative or structural role.

For now, the stone is a reminder that a single object can hold more than one story, and the rest of the building may hold more.

Sources

• Árbore Arqueoloxía e Restauración, excavation at Castro do Pico da Bandeira (director Nerea Vilariño); original announcement not located
• Arkeonews, 23 October 2026: Unique 2,000-year-old stone with two mysterious symbols discovered in Galicia