 However, archaeological finds from the Halstatt and La Tène culture were rare in the Iberian Peninsula, in southwestern France, northern and western Britain, southern Ireland and Galatia and did not provide enough evidence for a cultural scenario comparable to that of Central Europe.It is considered equally difficult to maintain that the origin of the Peninsular Celts can be linked to the preceding Urnfield culture.This has resulted in a more recent approach that introduces a 'proto-Celtic' substratum and a process of Celticisation, having its initial roots in the Bronze Age Bell Beaker culture.