frontiers of the roman empire travel landmark

vector illustration landmark limes borderlands fortifications frontier life defensive strategy military power complex architecture historical significance geographic boundaries diplomatic relations trading routes cultural interactions ancient engineering strategic placement romanization provincial governance security measures zs lookout towers walls barbarian invasions conquests civil roman expansion crossborder conflicts warfare tactical formations technology invasion prevention operations presence coastal defenses hillforts nerk of roads crossfrontier trade road safety diverse communities heritage barriers archaeological imperialism occupation international geostrategic importance deterrent