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Photo: Doug Knuth from Woodstock, IL, CC BY-SA 2.0 via Wikimedia Commons
Reputed to be the world’s largest cave by the British Caving Association. Only guided tour available but with group of limited persons. Tour costs USD3,000/person and requires 5 days and 4 nights. First group completed their exploration in early August 2013.
Sơn Đoòng Cave, in Phong Nha–Kẻ Bàng National Park, Quảng Trị province, Vietnam, is the world's largest natural cave.
© OpenStreetMap contributors
Dark Cave
A real adventure cave, still without the lights and large tourist groups to spoil the experience. Explore this spectacular cave on a National Park tour or independently, and after kayaking across the river, enjoy swimming through the cave with your headtorch leading the way, then explore a side passage. Hang Toi is a wonderful and very accessible example of the beautiful caves that are found throughout this region.
Discovered in 2016 by a local man, this cave has the potential to be the 2nd biggest cave in the world. The first tourists experienced this cave in 2017. Green Land Tours is the only company that offers access to each of the cave's two entrances. The tours are led by the man who discovered the cave and spent 2 years exploring it. The Ruc Mon Cave is named after the indigenous people who made a home at the entrance until the 1980s. The cave is 17 km long, with one entrance in Phong Nha-Kẻ Bàng National Park and the other at the border of Laos. This cave has the potential to be the second biggest cave in the world, following the first biggest cave also located in a Phong Nha. One of over 300 caves in Phong Nha Ke Bang National Park, this cave is probably the least-explored of the many caves open to tourists.