摘要: In this chapter, I discuss passive and mostly ‘low-tech’ defences in the shape of barricades (i.e. counter-intrusion devices) citadels facilities hardened against terrorist or criminal attacks). After all, my opinion, these modern avatars time-honoured brick-and-mortar curtain walls still have a formidable role to play times global terrorism: basically, they are our last line defence terrorists who managed evade all other high-tech measures described above without being detected now ready strike. Hence, will take look at city such as City London’s ‘Ring Steel’/Ring Glass’, One World Trade Center New York, (temporarily) deployed deny access certain areas.