lol ive lived in texas all my life and we knew about those tunnels since i was kid in the '70s. why do you think so much coke came in the U.S. sure they were flying it in, DEA knew that. but they didnt know about the tunnels. lol its funny to us wen people from the states were like dumbfounded wen they found out about the tunnels.
I guess that doesn't surprise me to hear you say that. You get a good enough engineer and you can do some amazing things to fortify those walls. That said, I would never want to be in one of those tunnels unless I was going to pull a nice heist. Claustrophobia.