#10 The Trans-Border Railway, 2010
Mexican marijuana traffickers took a page from American history and built their own version of an underground railroad—for a much less noble of a cause: transporting weed across the California-Mexico border. After following a suspicious truck to a Tijuana warehouse, police found the entrance to a freshly-excavated clandestine passageway. The 1,800-foot long tunnel was complete with a light rail system that smoothly delivered marijuana from a crawlspace on the California side. All in all, authorities seized 30 tons of pot worth $20 million. Fun fact: California had just voted against legalizing marijuana just two days earlier.