By Amanda Stringfellow @amanda_l_s
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Tham Khoun Xe, commonly known as the Xe Bang Fai River Cave, in Laos, has over 15km of passages filled with awe-inspiring views and wide expanses of water.
The massive cave ranks with Hang Son Dong in Vietnam, the Sarawak Chamber in Malaysia and the Miao Room in the Gebihe Cave System in China, as one of the largest sustained river passages in the world.
Photographer, John Spies, 59, captured scenes from the entrances of the huge underground river passages, intricate cave formations and views from a passage high above the water
The cave is formed by the Xe Bang Fai River, a major tributary of the Mekong and in the dry season can be traversed in the dry season using inflatable kayaks.
It is believed the largest chamber measures 400m by 230m and reaches a height of 160m above the river level.
The phenomenal natural features include a 61-metre gour pool believed to be the longest in the world, and some of the largest hexagonal shaped cave pearls ever found.
John, an Australian expat, was joined on the exhibition by his wife Suphaporn Singnakphum, David Pierce, from America and Stephen Brown, from Australia - all experienced cave explorers.
The photographer, who now lives in Indonesia, said: “During the dry season from November to April, the Xe Bang Fai river runs clear.
“It is this pristine river that not only formed the cave but also makes this cave so special.
“The through trip, negotiable in the dry season using inflatable kayaks, passes through seven kilometres of enormous river passage that is superbly decorated with massive flowstone formations that cling to the cave walls and giant stalagmites and dripstone formations on higher levels and banks along way.
“One section, the Oxbow area, has a massive expanse of gour pools, including the biggest known single pool in the world.
“Other spectacular formations include deposits of large cave pearls. Fossil passages near both ends of the cave extend for several kilometres.
“At the downstream end are large rooms heavily decorated with stalagmites and at the upstream end is an underground garden of low-light plants.
“I have traversed the main passage three times now, and it is not an easy trip as it involves carrying boats and gear over some long breakdown sections, but I will definitely be back to do it again.”