[BeauBo]

In San Diego, Tijuana (that's the one on the right) buts up along the border fence for 15 miles. That's how it is typically, one big urban area with a fence down the middle (in Texas, its a shallow river).

[Wuli]

I don’t care if it means occupying a swath of territory dividing a Mexican city, with military chekpoints at every intersection along the route - I’d do it. For those cities I’d have the wall all along the U.S. side with only U.S. checkpoints for any legal traffic between the two. And I’d move those U.S. checkpoints onto Mexican territory, until Mexico agrees to man them to stop illegals themselves.