Son Doong cave, located in an impoverished region of Vietnam near the border with Laos, is not only thought to be the largest natural cave in the world, it is also one of the most spectacular. First explored in 2009, it is immense. Its discovery made a huge difference to the lives of the desperately poor local community. But a debate rages: does mass tourism to the region risk destroying what made the cave so special in the first place? Or would restricting access to Son Doong mean that only the wealthy could benefit from it? This well-meaning documentary sounds an ecological alarm, but rather ties itself up in knots exploring the issue.
