Which national park in Vietnam contains the world's largest cave, Son Doong?

Phong Nha-Ke Bang National Park contains Son Doong, the world’s largest natural cave, in central Vietnam.

The park lies in Quang Binh Province within an ancient limestone-karst landscape shaped over roughly 400 million years. Its underground network includes hundreds of caves and rivers, making it one of Asia’s most important karst systems.

Son Doong was first explored by a British-Vietnamese expedition in 2009. Its enormous passage has its own underground river, jungle-filled dolines and weather patterns. A common mix-up is confusing Son Doong with Phong Nha Cave, the park’s better-known tourist cave; both are in the same protected area, but they are different caves. The park was established in 1986 and became a UNESCO World Heritage Site in 2003.