Field fortifications and tunnel systems are typically thought of as defensive and active protective measures, but the VC/NVA also employed them offensively. It was common for extensive field works to be constructed to support assaults and sieges on US fire-support bases and remote camps. Their tactics reflected attempts to counter the massive firepower they faced: when directly engaging the enemy they employed “hugging” tactics (moving in and remaining closely engaged, even intermingling units, to prevent the enemy from bringing his artillery and close air support to bear). Their field works included defended villages, base camps, fortified complexes, hilltop defenses, trench systems, individual fighting positions, crew-served weapon positions, bunkers, caches, and extensive tunnel systems. Camouflage and deceptive measures, and the employment of obstacles and booby traps went hand-in-hand with such field works. This book examines these unique fortifications.