unesco world heritage site, arches of roman amphitheatre at archaeological park, xanten, north rhine-westphalia, germany

archaeologischer rhinewestphalia archaeological amphitheatre amphitheater architecture constructed foundations archaeology destination niederrhein settlement westphalia flagstones inferioris fortified frontiers germaniae limestone rhineland heritage original circular cultural frontier germanic historic imposing pavement germany regular partial replica colonia traiana western arcades borders columns emperor harbour history pattern tourism tourist trajana unesco arches xanten german empire border europe trajan travel