In other news , Yemen is a giant strip of fried bacon . <| sep |> I have actually given this quite a bit of thought . Before I go on , let me preface this by saying that , yes , I know there are quite a few vulnerabilities in my idea , but I have given thought to contingencies for each one . First off I would only need two small sections of wall . Everyday I drive past this section of highwayHighSchool 40 . 2099523 , 79 . 9860469 , 1464 mdata ! 3 m 1 ! 1 e 3 ! 4 m 5 ! 3 m 4 ! 1 s 0 xtel 81114 d 0 x 16 b 67 e 4762 abee 03 ! 8 m 2 ! 3 d 40 . 2002157 ! 4 d 79 . 9790665 . This is a long expanse of bridge . It is a very high bridge with hills on both sides of the road leading up to , and away from , the bridge . One side would have a wall built with a large gate like they had at the prison towards the end . One that opens outward so that a large herd could not force it open . The wall would have barriers that would move the herd along it ' s outer path towards the edge . This only requires a small amount of wall to be built because any other walkers would just fall off the edge . The other end , I would put up a wall directly onto the Bridge and would then remove a large section of the highway so nothing could just walk onto it . The gate on that end would be like a draw bridge from a medieval castle . I would line the outer edges of the bridge with trailers and campers and such for supplies and living quarters . The inner lanes would be the common areas with large covered areas . The gap between the two bridges would have walkways every 50 feet or so to allow the inhabitants to move from one side to the next . At either end of the bridge I would have towers built to allow for a long visual to watch for threats .