Son Doong Cave, which is located in Quang Binh Province in Vietnam near the Lao border, is the world's largest known underground cave. It is so big that the cave is said to be able to accommodate 15 of the Great Pyramids of Giza and the passageways can accommodate a Boeing 747 plane.
Son Doong means 'mountain river' in Vietnamese. Compared to other limestone caves, this cave is relatively young. Son Doong Cave was formed 2-3 million years ago inside the largest limestone massif in Asia, a colossal rock mass over 400 million years old made of compressed shells and skeletons of ancient marine animals.
Discovery and Uniqueness of Son Doong Cave
Son Doong Cave | CNN/Jarryd Salem
Two rivers, Rao Thuong and Khe Ry, flow through the cracks in the limestone and slowly erode it, forming a large tunnel in the rock that is now known as Son Doong Cave. The cave was discovered accidentally by Ho Khanh, a Vietnamese local, while he was hunting in the forest in 1990.
According to Howard Limbert, a British explorer, there is no evidence that humans ever inhabited Son Doong Cave in the past. One reason is that all access to and from the cave requires a near-vertical descent of at least 85 meters with special equipment. In contrast, a stone axe was found in a cave located nearby that is about 5,000 years old, indicating that the inaccessibility of Son Doong Cave may have prevented exploration by prehistoric humans.
Limbert explained that Son Doong Cave holds many interesting things. He and his team discovered seven new species, including fish, spiders, scorpions, shrimp, woodlice, and plankton. All of these creatures are white and have no eyes, the result of an evolutionary process that occurs due to living in a permanently pitch-black environment.
Son Doong Cave's Ecosystem
Son Doong Cave | Oxalis Adventure Tours/Ryan Deboodt
Inside the Son Doong Cave, tourists will find underground rivers, dense forests, and stunning stalactite and stalagmite formations. Some areas of the cave even allow sunlight to shine through, creating dramatic and otherworldly views.
The very large size of the Son Doong Cave helps the formation of clouds right inside the cave from underground rivers. In winter and spring, there is a giant lake near the cave's exit. This lake is very large and very deep so visitors have to use a boat to cross this area to continue their journey.
The Journal of Cave and Karst Studies study explains that Son Doong Cave was formed thousands of years ago and is now home to rare plant and animal species that are not found anywhere else.
However, this cave is still very rarely touched by humans. Only a few tourists can visit it, and even then only with special permission and accompanied by a professional guide from Oxalis Adventure, an official tour operator of which Howard Limbert is co-technical director with his wife, Deb.
Tourists who want to explore this cave can take a four-day tour for $3000, of which $660 is allocated to Phong Nha Ke Bang National Park, where Son Doong Cave is located.
The presence of a network of caves in Central Vietnam has brought about a major change in the region. What was once one of Vietnam's less developed areas has now become the world's most popular cave tourism destination and one of the country's fastest-growing tourist destinations.
Sources:
Harian Jogja. (2023). Menjelajahi Hang Son Doong, Gua Terbesar di Dunia dengan Panjang 9 Kilometer. https://wisata.harianjogja.com/read/2023/10/30/504/1153372/menjelajahi-hang-son-doong-gua-terbesar-di-dunia-dengan-panjang-9-kilometer
Detikjabar. (2024). Megah dan Indahnya Han Son Doong, Gua Terbesar di Dunia. https://www.detik.com/jabar/berita/d-7624496/megah-dan-indahnya-han-son-doong-gua-terbesar-di-dunia
Radio Republik Indonesia. (2025). Son Doong, Surga Bawah Tanah yang Megah dan Keajaiban Alam Tersembunyi. https://www.rri.co.id/wisata/1401554/son-doong-surga-bawah-tanah-yang-megah-dan-keajaiban-alam-tersembunyi
