Walls have been part of just about every culture throughout history, and with good reason. For centuries, people everywhere have seen the need to defend their communities, cities or entire countries from unwanted intruders. Walls have also been used historically to draw clear lines between opposing peoples. We also know that walls can be used symbolically as a means of memorializing or remember important people and events. Here, the wall experts at Permacast Precast Concrete Fencing & Walls review some of the most famous walls in history.