Crotal bells (Greek 'crotalon' - castanet or rattle) are various types of small bells or rattles. They were produced in various Pre-Columbian cultures. In Europe they were made from probably before the early middle ages and though many founders cast bells of this type, the Robert Wells bell foundry of Aldbourne, Wiltshire produced the largest range. The first medieval designs came in two separate halves into which a metal pea was introduced and the two halves were then soldered or crimped together. Somewhere around 1400 they were cast in a single piece with a ball of metal inside.