Tu Lan cave system

Fabulous river caves in the idyllic setting of the Sogn Nan river valley makes Tu Lan a memorable place to cave. The approach to the town of Han Mho enters the river valley of Sogn Nan enclosed by limestone tower Karst. Emerald green fields of rice are passed divided by an intricate network of irrigation channels. From the village the land is used for grazing cattle and Buffalos are happily wallowing in the small water holes dotted across the fields. Beyond the walk leads through cultivated land of Maize before dropping to the glistening warm waters of the Song Nan. Wading across the river with the back drop of cultivated land and the tower Karst is stunning. Ahead, cave entrances appear. Above the main sink to the left is Rat Cave, a dry fossil cave surveyed in 1992 and is used to reach the La Ken valley, which may be an important area to find the missing link between the Tu Lan/Hang Ken system and Hang Tien. In 2010 the expedition spent some time looking for caves in this area, however the guides at the time knew of no caves other than the exit of Hang Ken. This year whilst caving with the Oxalis group they told us of a new cave known as Gibbon Cave. The cave was found in the jungle high above the resurgences explored in 2010 of the Song Nan as it enters the La Ken valley. Gibbon cave is the translation of Hang Uoi, a pleasant cave and is now used as part of the adventure trips to the area. A steep scramble up through the jungle soon leads to a large entrance. The cave starts as easy walking in a well decorated passage with many large cave pearls littering the floor. A large pit in the floor prevents further progress however a sneaky squeeze through the stal on the right side led to an exposed traverse. The traverse is best protected with a hand line and the way on is more decorated cave passage and calcite false floors but sadly soon closed down.
An objective of 2012 was to return to Tu Lan and push the two leads at the end of the cave in the hope of finding a way on inside the cave. We had also met with the Oxalis team who were keen for us to help survey and check out caves for use with groups and led us to explore a number of caves that we had previously missed or by passed in the belief that they were short and used as thorough fares for wood cutters.
Our first trip to Tu Lan was heading for a washout due to a massive thunder storm and with rapidly rising water levels we decided not to push Tu Lan. Whilst sitting at camp Howard was dutifully performing his ambassador role and was asked to give a TV interview at Han Mo. Chuckling Martin and I swung lazily with a brew in our hammocks soaking up the impressive entrance of Hang Ken as Howard was escorted away to be interviewed. Minutes later it appeared Howard had done a runner as he ran into camp out of breath, 'you better come and see this' he remarked trying hard not to give away his obvious excitement. Five minutes later we were all stood inside a narrow entrance passage with a large passage opening up in front, but this was not To Mo! Amazingly tucked behind the trees and out of sight was an overflow river bed and cave resurgence that linked with To Mo and more importantly it had by passed the sump in To Mo. A short exploratory trip ended when we reached a large river. We were not equipped and again with perceived high levels of water we left the cave. The Cave was named Hang Kim. Confident the sink was in the doline below the second col we diverted there on the walk out. Entrances were located and we were confident that these were the loggers cave and the sink for Hank Kim. Our guide was sure of a quick way back and took a different route back. Hours later we arrived in the first doline from a different angle having descended one of the scariest ladders ever.
On our next trip we agreed to check out the river passage that flows through the second col and we had previously been told was used regularly by wood cutters to bring timber through. This was known as Hung Tong and comprised of the active lower cave and Hang Hung Ton a dry fossil passage above. The dry passage above was explored to a pitch overlooking a passage which dropped to the final lake of the lower cave. When we returned later in the expedition we were amazed to find the Oxalis team had commissioned the construction of a homemade ladder made from 6'' square timber and lashed together to scale the 10 m drop, yet another example of Vietnamese ingenuity to overcome a minor obstacle.
We had chosen to use boats for the adventure and provided a firm dry platform for surveying. Unfortunately the passage narrowed and we had to carry the boats through the narrows and over a number of large blocks and trees jammed in the passage. Whilst negotiating this disaster struck, a tree 'traverse' collapsed sending Martin crashing heavily to the river and rocks below. Carrying a heavy pack exasperated the situation as he landed heavily onto his right elbow. Clearly in pain and an examination of the elbow suggested a fracture was likely, however Martin was determined to carry on and stoically he continued with the trip. We exited the cave in a magnificent enclosed valley which is referred to as the Tu Lan valley and provided us with a subsequent stunning bivi site. The Oxalis team had walked over the col and dropped down to meet up and cook lunch. This was a whole new dimension to caving. We fed Martin the best drugs we could rifle from the first aid drum and this was where his addiction began. However they did the trick and he was ready to explore again. The continuation of the river we knew sank into a cave further downstream and certain to be the same river in Kang Kim and Hang Mo. With the help of the porters the boat was carried to the entrance and the river passage again explored by boat, however this time only one was used as we punctured the second on the razor sharp limestone. A second entrance to the cave was discovered during the survey before we swam and paddled downstream. A large river was followed passing a number of cascades and a large mud bank before confirmation of the connection was made. We returned to the bivi site to find a very rickety hammock frame had been made for us. The jungle men of Minh Hoa are certainly second division compared to Quang Binh guides and was clearly demonstrated with this structure. Within seconds of lying in our hammocks it collapsed sending us sprawling to the floor in fits of laughter. Martin and I abandoned hammocks and went for the floor. Jon persevered and reconstructed a make shift frame.
We left Tu Lan and sent Martin for an x-ray which confirmed he had chipped a bone on his ulnar. Determined not to have to give up caving he spoke to Dr John Burton in the UK for some advice. He was given a half plaster cast to support his arm and with a cocktail of painkillers enabled him to carry on with the expedition.
On our final trip this year to Tu Lan we were determined to make the end leads of Tu Lan. Again we were joined by the Oxalis team. We helped survey the final cave that went through the first doline, Hang Son Oxalis is reached by an easy scramble to the entrance but be we were acutely aware of the dead branches that may collapse! A climb down blocks into the cave (10m hand line useful) crossing a stagnant pool on mud coated rocks desperate not to slip into the scummy pool. Ahead it was necessary to climb the boulders ahead with flood debris littered throughout. A Large impressive tunnel was then followed requiring some boulder hopping. An entrance on the left is passed which is probably the one below the timber cresta run on the first col. The cave passes some fine formation just before exiting in the large cultivated doline which then leads to the second col or Hang Ton. We chose to follow the cave systems to the To Mo valley where Tu Lan and Hang Ken entrances lie. We were met there by the Oxalis team and another wonderful banquet. That night Jon, Martin and myself headed off by boat into Tu Lan. The advantage of a boat was the attachment of a torch to the front so that we could turn off our own lights to escape the swarm of moths. The boat had to be man handled over the cascades but in the main passage was a relaxing and far quicker method of travel. The large inlet on the left was climbed high above the river but led nowhere and proved somewhat challenging to descend safely. The inlet to the right was pushed in a diminishing size passage to a pit and the sound of running water below. By combined tactics I was part lowered part climbed and part slid down a rope only to find a sump a short way on.

Tu Lan is a truly amazing place and a connection to Hang Tien is sure to discover more stunning cave. This will require longer trips into the jungle and some time spent to find guides who have travelled deeper into the jungle and have better knowledge of possible caves.
Martin Holroyd


2012 Report


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