At the beginning of the second century of the modern era, a fortification of more than 100 km in length was built to protect the Roman Empire from the ‘barbarians’. Three centuries later, Hadrian’s Wall was abandoned forever. What is left of it, a UNESCO world heritage site, is now visited only by tourists. The route taken by the Wall corresponds roughly to the current border between Scotland and England, a border that is not destined to be adorned by watchtowers and barbed wire...