5. A small fence separates densely populated Tijuana, Mexico , right, from the United States in the Border Patrol's San Diego Sector . Construction is underway to extend a secondary fence over the top of this hill and eventually to the Pacific Ocean .
17. “ This obsession with physical security systems, and, collaterally, with the architectural policing of social boundaries, has become the zeitgeist of urban restructuring, a master narrative in the emerging built environment of the 1990’s”
