Phong Nha-Kẻ Bàng
Phong Nha-Kẻ Bàng National Park is located in the karst mountains of Central Vietnam, on the border with Laos, north of Huế. You visit for its caves, including Sơn Đoòng, the world's largest known cave, and several stalactite caves that you can visit without an expedition.The karst is around 400 million years old and is considered Asia's oldest major karst region, with over 220 kilometers of documented caves and underground rivers. Since 2003, the park has been a UNESCO World Heritage site, and in 2025, the site was expanded to include the adjacent Hin Nam No National Park in Laos.The starting point is Phong Nha town, about 45 kilometers west of the coastal city of Đồng Hới, with guesthouses and tour operators. Two to three days are sufficient for the accessible caves, while multi-day cave tours must be booked long in advance. Since July 1, 2025, the area has belonged to Quảng Trị Province, which was merged with Quảng Bình.