Dong Hoi, a tranquil coastal city in central Vietnam, lies near the former Demilitarized Zone (DMZ) that once divided North and South Vietnam. Although heavily damaged during decades of conflict, the city has been remarkably rebuilt and today serves as the main gateway to Phong Nha–Ke Bang National Park, located about 50 kilometres to the northwest. Recognized as a UNESCO World Heritage Site, the park is renowned for its extraordinary limestone karst landscape and some of the world's most spectacular caves. During the First Indochina War, Dong Hoi Airbase was used by French forces to launch operations against the Viet Minh in north-central Vietnam and the Pathet Lao in neighboring Laos, reflecting the city's significant strategic role in the region's history. Vietnam Bike Tours