EDHS Contemporary World Affairs

The latest secret passage -- equipped with a hydraulic lift, electric rail carts and a wooden staircase -- was discovered Tuesday on the U.S.-Mexico border, highlighting an emerging seasonal trend. For three years, authorities have found sophisticated tunnels shortly before the winter holidays in what officials speculate is an attempt by drug smugglers to take advantage of Mexico's fall marijuana harvest.

The discovery of the 600-yard tunnel resulted in seizures of 32 tons of marijuana, one of the largest pot busts in U.S. history. It linked warehouses in San Diego and Tijuana and was equipped with lighting and ventilation. Wooden planks lined the floor about 40 feet underground.