Kate, one of Selective Asia's adventure travel specialists, recently returned from a research trip around Vietnam and Cambodia. One of her most spectacular stops was at Phong Nha Caverns, the vast complex of caves and underground rivers beneath Phong Nha-Ke Bang National Park, near the Laos border in central Vietnam.
While she was away, we showed you a selection of the most impressive caves in South-East Asia, and promised to put some of Kate's photos of Phong Nha on display when she got back.
They're all taken in what's known as 'Paradise Cave' or Thiên Đường, which was only discovered in 2005. At just over 19 miles long, it's the largest chamber found so far in Phong Nha.
Kate says, 'we did go to Dark Grotto (Hang Tối) as well, but couldn't take cameras, as there was a lot of kayaking - and walking through chambers waist-deep in mud!'.
Paradise can reach up to 100 metres high, and 150 wide, with limestone formations considered by many to be the most spectacular (discovered by modern humans, at least) in the National Park. Huge stalactites descend from the shadows above, forming mighty columns that gleam in the thoughtfully deployed lighting (no Wookey Hole witches here, thank you very much).
Although parts of the cave system have been known about - and sometimes occupied - since at least the 7th century, a great deal remains undiscovered about Phong Nha, & its place in human history.