The Huyen Khong cave on Thuy Son Mountain is probably the most important attraction in the Marble Mountains. I went into this cave without knowing anything about it and what I discovered was so exciting!
Before you arrive at the actual cave, there is a smaller cave with a figure of a standing Buddha. To the left, there's a small passage way which leads to stairs which descend to a very special place: the Huyen Khong cave.
If you're lucky enough to visit the cave when it's empty, you'll feel like you're in a movie. The cave seems like a cathedral and in the enormous main gallery there are statues of administrators and Mandarin soldiers guarding the cave as well as various Chinese and Confucian altars scattered around the interior.
There is a small hole in the ceiling of the cave which allows natural light to filter through and add to the cathedral atmosphere. The cave was used by the Viet Cong as a field hospital.
One of the many caves of the Marble Mountains is the Hoa Nghiem Cave, smaller than the others, it is important because it has a statue of "Female Buddha" (Goddess of Mercy) very common in Vietnam, known as Quan Am Thi Kinh, carved in stone.