▁of ▁the ▁fort ification ▁system , ▁domin ates ▁the ▁Rh ine ▁Valley ▁to ▁this ▁day . ▁ ▁The ▁following ▁cast les ▁are ▁found ▁along ▁the ▁Middle ▁Rh ine , ▁in ▁down stream ▁order : ▁ ▁History ▁ ▁Pre history ▁ ▁The ▁terra ces ▁of ▁the ▁Middle ▁Rh ine ▁Valley ▁have ▁been ▁inhab ited ▁since ▁the ▁early ▁Iron ▁Age . ▁ ▁Ev idence ▁of ▁this ▁are ▁the ▁bar row ▁fields ▁around ▁the ▁city ▁forest ▁of ▁Bo pp ard ▁and ▁in ▁the ▁forest ▁of ▁Bre y ▁and ▁the ▁ring ▁walls ▁on ▁the ▁D omm el berg ▁in ▁Kob len z ▁and ▁on ▁the ▁giant ▁hill ▁at ▁St . ▁Go ar sh aus en . ▁ ▁On ▁the ▁western ▁border ▁of ▁the ▁Middle ▁Rh ine ▁region , ▁there ▁are ▁also ▁traces ▁of ▁a ▁C elt ic ▁settlement , ▁with ▁the ▁grave ▁pill ars ▁of ▁Pf al z feld ▁and ▁the ▁Wald al ges heim ▁ch ari ot ▁bur ial . ▁ ▁In ▁the ▁ 4 th ▁century ▁B CE , ▁the ▁area ▁had ▁come ▁under ▁the ▁influence ▁of ▁Mediter rane an ▁civil izations . ▁ ▁The ▁north - s outh ▁link ▁between ▁mouth ▁of ▁the ▁Na he ▁and ▁the ▁Mos elle ▁est u ary ▁rich ▁already ▁in ▁use ▁in ▁pre - R oman ▁times . ▁ ▁The ▁Roman ▁development ▁of ▁the ▁route ▁over laps ▁in ▁large ▁sections ▁with ▁the ▁route ▁of ▁the ▁modern ▁Bundes aut ob ahn ▁ 6 1 ▁ ▁Roman ▁period ▁ ▁The ▁Rom ans ▁settled ▁in ▁the ▁area ▁of ▁the ▁Middle ▁Rh ine