Bann disc
The Bann disc is an Iron Age bronze artefact that was discovered in the River Bann near Coleraine, Northern Ireland, in 1939. It is a thin decorative piece emblazoned with a La Tène-style triskelion, with no obvious practical purpose. The emblem of the Coleraine Historical Society is based on the disc and its annual publication is called The Bann Disc Journal. It is currently on display in the Ulster Museum. References 

Archaeological artifacts
Iron Age Europe
La Tène culture
1939 archaeological discoveries
Coleraine
Ancient Celtic metalwork
Archaeological discoveries in the United Kingdom