/mexico border into the tangle of tunnels used to traffic not only drugs but high-level drug kingpins emselves. been discovered and abc's matt gutman takes us for an up-chose look. >> reporter: in that beige garage is a multimillion-dollar hole in the ground. and we're about to stuff oursrsves into it. my god, is it dark and chaus tro phone nick here. this is terrifying. we are the only news team ever to go down that hole. >> that's a spike my head nearly went through. >> reporter: crab-walking our way down a former drug smuggling tunnel between the u.s. and mexico, one of the wayshat tens of billions of dololrs of drugs are trafficked into the u.s. every year. u.s. and mexican authorities have found and destroyed over 180 tunnels along this border. the question they s isn't whether there arere more tunnels, but how many and where. much of what what's funneled beneath is the product of the leader busted out of prison earlier this year but having his come raids tunnel right into his prison cell. a tunnel fitted out with a motorcycle on a rail. notorious not onlnl for his narrow escapes and pris