wearethemighty.com
Why the Viet Cong's tunnels were so effective
‚ÄčThe tight, cramped tunnels were a crappy place to live, but a brilliant place to defend. They were used as secret resupply routes and staging areas by communist insurgents. But for U.S. troops attempting to clear them, they were a nightmare. It was hundreds of miles of tunnels filled with booby traps and poisonous animals.