▁used ▁in ▁the ▁Middle ▁A ges ▁as ▁the ▁boundary ▁of ▁V arz im : ▁Ver az im ▁... ▁subt us ▁m ons ▁civ itas ▁Ter ro so ▁disc urrent es ▁aqu as ▁ad ▁mare , ▁territorio ▁Bra ch ara ▁( J une ▁ 2 5 , ▁ 1 2 0 2 ). ▁The ▁expression ▁" sub t us ▁m ons " ▁is ▁typical ▁on ▁the ▁Portuguese ▁medieval ▁documents ▁and , ▁as ▁it ▁was ▁proved ▁by ▁Fer re ira ▁de ▁Al me ida , ▁it ▁is ▁not ▁just ▁a ▁top ographic ▁dependency , ▁but , ▁especially , ▁an ▁administrative ▁and ▁military ▁dependency . ▁ ▁C iv idade , ▁with ▁São ▁F éli x ▁Hill , ▁extends ▁from ▁the ▁small ▁Ser ra ▁de ▁R ates ▁mountain ▁range . ▁It ▁is ▁the ▁second ▁highest ▁hill ▁in ▁P ó vo a ▁de ▁V arz im , ▁after ▁São ▁F éli x ▁Hill . ▁ ▁Pro to histor ic ▁city ▁ ▁C iv idade ▁de ▁Ter ro so ▁was ▁an ▁important ▁city ▁of ▁the ▁Castro ▁culture ▁in ▁North - western ▁I ber ian ▁Pen ins ula , ▁established ▁during ▁the ▁Bron ze ▁Age , ▁between ▁ 8 0 0 ▁and ▁ 9 0 0 ▁BC , ▁as ▁a ▁result ▁of ▁the ▁disp lacement ▁of ▁the ▁people ▁inhab iting ▁the ▁fert ile ▁plain ▁of ▁P ó vo a ▁de ▁V arz im . ▁ ▁The ▁most ▁typical ▁characteristic ▁is ▁its ▁def ensive ▁system . ▁The ▁inhabitants ▁had ▁chosen ▁to ▁start ▁living ▁in ▁the ▁hill ▁as ▁a ▁way ▁of ▁protection