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Oppidum (Latin for "town"), name of a fortified mountain settlement of the Celts. Celtic oppida came into being from the 2nd century B C on Braunsberg mountain, on Freinberg mountain near Linz, and on Umlaufberg mountain near Altenburg, to name a few. In Roman times, "oppida" was the general term for town (lower in rank than "municipium" or "colonia"), in the Middle Ages, the term was used (up to the 13th century) to mean a fortified larger settlement (town); at the same time the terms "forum" or "civitas" were also used to mean the same thing (e.g. Völkermarkt was referred to as "forum" from 1248-1267, "civitas" in 1252 and 1254, and "oppidum ducis" in 1266).