[drpix]

There's no great mystery about what works. Even India has had one for years, that would work fine - without spending the tens of billions the open-border crowd is claiming

"This is What the India-Pakistan Border Looks Like at Night From Space" - ndtv.com

It's so over 2,000 miles long and can be seen from space. Here's some photos"

[Joe 6-pack]

Not bad, but could use a crocodile filled moat...