Phong Nha-Kẻ Bàng is noted for its cave and grotto systems as it is composed of 300 caves and grottos. A 2009 survey brought the total discovered length of the cave system to about 126 km., with many areas still not well explored. The Sơn Đoòng Cave, which was discovered in the 2009 survey by British … Continue reading Paradise cave – Kayaking in Chay River – Explore Dark Cave