Soldier prepare a ladder to enter a tunnel during a presentation to the media in Tijuana November 16, 2011. Police have discovered a "major cross-border drug tunnel" running to California from Mexico, and seized 14 tons of marijuana, authorities said Wednesday. The tunnel links warehouses in an industrial park south of San Diego and the Mexican border city of Tijuana, the U.S. Immigration and Customs Enforcement agency said in a news release. REUTERS/Jorge Duenes (MEXICO - Tags: CRIME LAW DRUGS SOCIETY MILITARY)
A look at various smuggling tunnels across the U.S.-Mexico border.