oppidum

To the Romans, an oppidum (pl: oppida) was Latin for the main settlement in any administrative area. Julius Caesar described the larger Iron Age settlements he encountered in Gaul as oppida and the term is now used to describe the large pre-Roman towns that existed all across Western and Central Europe. Many oppida grew from hill forts although by no means all of them had significant defensive functions. Oppida surrounded by earthworks are known as enclosed oppida. The development of oppida was a milestone in the urbanisation of the continent as they were the first large settlements north of the Mediterranean that could genuinely be described as towns. Caesar pointed out that each tribe of Gaul would have several oppida but that they were not all of equal importance, perhaps implying some form of hierarchy. In conquered lands, the Romans used the infrastructure of the oppida to administer the empire and many became full Roman towns. This often involved a change of location from the hilltop into the plain. Examples of oppida:

Bibracte (Mont Beuvray), France
Manching, Germany
Stradonice, Bohemia
Basel-Mnsterhgel, Switzerland
Traprain Law, Scotland

Oppidum

Further reading