Vịnh Mốc ([vɨn˨˩ʔ məwk͡p̚˦˧˥] vin-mouk) is a tunnel complex in Quảng Trị, Vietnam. During the Vietnam War it was strategically located on the border of North Vietnam and South Vietnam. The tunnels were built to shelter people from the intense bombing of Son Trung and Son Ha communes in Vinh Linh county of Quảng Trị Province in the Vietnamese Demilitarized Zone. The tunnels were a success and no villagers lost their lives. The only direct hit was from a bomb that failed to explode; the resulting hole was utilized as a ventilation shaft. Three levels of tunnels were eventually built.