Over 150 Iron Age objects deposited in a lake including slave chains, chariot fittings, and swords. Some items were imported from across Britain. A major pilgrimage center for 200 years.
Porius1, CC BY-SA 3.0, via Wikimedia Commons
An accidental wartime discovery
In 1942, during the construction of the RAF Valley airfield on Anglesey, workers dredging peat from a bog made an unexpected discovery. The first object to surface was a long iron chain, initially mistaken for modern equipment and used to tow trucks. A worker, William Owen Roberts, eventually had it identified. It was a 2,000-year-old gang chain for holding multiple captives. This triggered a more thorough search, and over the following months, more than 180 metal artifacts from the Iron Age were pulled from the peat.
Scientific dating shows these objects were deposited over a long period, from approximately 300 BCE to 100 CE. The collection is one of the largest assemblages of La Tène style Celtic metalwork found in the British Isles. The site was once a small lake, and the anaerobic conditions of the peat bog preserved the metalwork in remarkable condition. Pollen analysis of the peat layers reveals that the Iron Age terrain surrounding the lake consisted of open heath and grassland.
A catalogue of ritual offerings
The objects from Llyn Cerrig Bach represent a cross-section of high-status Iron Age society. The collection is overwhelmingly military, with seven swords, six spearheads, and fragments of a shield boss. It also contains numerous parts from chariots, including iron wheel tires, bronze fittings, and bridle bits. One of the largest items is the iron gang chain, which is over 3 meters long with five neck rings, weighing 6.66 kilograms. Another similar chain was also found.
Analysis of the metalwork reveals that the items came from various locations. Some pieces show stylistic links to Somerset and southern Britain, while others may have originated in Ireland. This wide geographic range suggests that Llyn Cerrig Bach was a religious site of far-reaching importance. The dominant interpretation is that these items were votive offerings, deliberately thrown into the sacred waters over many generations. Many of the weapons, such as swords, were bent or broken before being deposited, a common feature of ritual sacrifice of objects. The Roman historian Tacitus described Anglesey as a major center for Druids, and the lake was likely a focus of their religious activities before the Roman conquest of the island in 60/61 CE.
💡Fun Facts
The first object found, the 3-meter-long iron slave chain, was used by airfield workers to pull vehicles from the mud before its true age was realized.
The original discovery site is now inaccessible to the public, located on the grounds of the active Royal Air Force station, RAF Valley.
A decorated bronze plaque found in the lake features a triskele design, a classic motif in La Tène art, with parallels to Neolithic carvings at sites like Newgrange in Ireland.
In 2024, new discoveries were made at the site, including a complete horse bridle-bit dating to around 60 AD and a rare rein-guide ring with red glass inlay.
The original site at RAF Valley is inaccessible. The artifacts are on public display at the National Museum Wales in Cardiff, which is typically open Tuesday-Sunday, 10am-5pm.
