Among the earliest objects in the La Tene style found in Wales is the Cerrigydrudion hanging-bowl, which dates from about 400 B.C. Many examples of La Tene art were imported into Britain, among them the Merthyr Mawr brooch and the Coygan bracelet, but it is believed that the style struck roots within Britain itself, giving rise to regional schools of talented metal-workers. South-eastern England was the most productive area; it was there, around 100 B.C., that objects such as the Trawsfynydd tankard and the Capel Garmon fire-dogs were made. Wales also had craftsmen working in the highest traditions of La Tene; the beautiful plaques found at Tal-y-llyn, for example, were made of metal smelted from ore mined at Nantyrarian near Aberystwyth. Over half the examples of La Tene art found in Wales were discovered in Anglesey; there, in 1942, almost a hundred metal objects belonging to the most developed period of the style came to light at Llyn Cerrig Bach. A large number of them are associated with the art of horsemanship, but they also include plaques adorned with the characteristic motifs of La Tene. The sources of the collection are varied; they include the work of the craftsmen of Ireland, Yorkshire and south-eastern England, proof of the presence in Anglesey in the years between 150 B.C. and AD 50 of men of far-reaching influence, thus confirming documentary evidence that the island was the chief centre in Britain of druidical religion.

Source ~~ A History of Wales by John Davies