A tunnel that stretches from a former Kentucky Fried Chicken in Arizona all the way to a home in Mexico was discovered last week by investigators, who believe the secret passageway was used for drug smuggling, KSWT reports.

Multiple agencies, including the Oklahoma Bureau of Narcotics (OBN) and the Homeland Security Investigations (HSI,) shut down a large-scale, Mexican-sourced meth manufacturing operation in Oklahoma City.