Hang Ken/Tu Lan
By chance whilst trying to find a map of Quang Binh on the internet I found a link on caves of the Minh Hoa area with articles of large river caves 6km long and still continuing. Howard had identified this as an area to return to in 2010 and this article further confirmed the potential. Previously visited in the earlier expeditions very little had been done in the area with only a handful of discoveries to date. A small recce team of Phong, Deb, Sweeny and myself headed off in search of the guide who featured in the web article. By chance we were directed to the town of Han Mho situated in stunning scenery, a mixture of Emerald green paddy fields, cultivated farm land surrounded by stunning tower Karst. The usual ritual of chasing permissions resulted in an interesting night on the Vice Presidents floor and a bleary eyed team set out the following day. From the town of Tan Hoa it is possible to drive across the fields to the north of the village and the Song Nan River. When the cultivated fields prevent further vehicular access a pleasant walk crossing the river and paths through the maze fields led to a sink with flood debris high above. The cultivated area borders the jungle and gives a fascinating contrast; a good path led us through the jungle with the obligatory hills, exposed climbs and biting stinging bugs and plants. We dropped steeply to an impressive enclosed doline. The impressive resurgence of Hang Ken is obvious on the left as the valley floor is reached. A GPS fix and referenced with the map put us in a small enclosed doline but no river was marked which was odd as the large river bed and existing river would appear to be very significant Convinced that the map or GPS must be incorrect we wildly speculated and tried to make the landscape fit the map and the marked rivers 2km to the north. We had however arrived at a stunning location and a camp ground soon formed and the pot on.The trees for the hammocks were shallow rooted as I was soon to discover, when testing the hammock the tree uprooted and a hard landing was only avoided by the lighting reactions of Sweeny supporting the tree(primarily for self preservation as he was in the direct fall line) did I get some stick!
With a choice of caves we chose Hang Ken the large impressive resurgence upstream of our campsite.The entrance is easily reached by scrambling over boulders to an impressive entrance arch 15m high and 30m wide.I had already chosen to put on my wetsuit at the camp ground much to the amusement and ridicule of the others. The large entrance lake however was hidden from view until an easy scramble up the boulders revealed the true beauty of the cave and of course the lake, my turn to laugh. Caving with Sweeny is always educational and full of Innuendo’s. Soon Hang Ken was linked to Coronation Street and Deirdre. What?Picture the scene, an easy swim across the lake with Sweeny (egged on by Deb it has to be said) in full fantasy innuendo, wet passage, doggy fashion and I sang the infamous Toy Dolls song Deirdre is a slag. An obvious bend in the river with a large dry passage above brought an immediate reaction from Sweeny“I wonder if Deirdre is a goer” The passage was aptly named but would wait for later. The main river passage continued in fine style with numerous swims, occasional climbs and cascades. The end of the cave changed abruptly and the main flow may have been missed. The river passage ends at a large shingle bank and the source of the river is lost. Ahead the passage splits into smaller passages, a wet canal on the left appears to double back on itself and was only explored a short way with no conclusion. Ahead the passage ends at a large calcited breakdown area. A route was found to the left and appears to be a sink inlet this was followed for about 250m to a complete choke but evidence of roots and surface debris.
Back on the surface we settled down to cooking the dinner on the open fire and stubbornly insisted on boiling the brew water on the spluttering fire rather than the primus stove, we went to bed late!
Our objective the next day was Deirdre is a goer, or, as we joked would she have a headache? The passage was easily reached by a simple climb up calcite to a large impressive dry passage starting as an easy walk passing many large calcite formations. The passage becomes smaller and the obstacles more abundant, climbs across boulders with friable hand holds, slippery mud and sharp blocks along with cold pools of water that are a mixture of wading and swimming to cross. The passage closes down dramatically and just when it appeared to be finishing dramatically drops into a large active river with a strong current. Time was now against us and we made the decision to see if the river might be the unexplored cave back at the Doline, a short recce confirmed that this was a significant passage and daylight could be seen in the distance, however the flow was the wrong direction so we could not chance going out this new way and returned the way we had come.
This had been a stunning recce with over 3km surveyed, going leads and hitherto unexplored caves.
We soon returned along with Howard, Anette, Carsten and Robbie, this time to explore the sink of Tu Lan. Howard was amazed that we had left such an incredible sized cave. The first trip saw Sweeny and me paired up to push the stream, Howard, Deb and Anette to survey the dry entrance and the Nat Geo boys to take some photos. The dry entrance connects to the streamway a short way downstream where we found the trio sat in darkness to avoid the swarm of flies and moths being attracted to the lights. The survey was connected and we left the others to take photos Sweeny and I set off downstream. The moths were unbearable and at every opportunity we would switch our lamps off. It was whilst sat in the darkness I heard the sound of something swimming close by. I was initially startled when I switched my lamp on to see what appeared to be a snake swimming towards me. On closer inspection the flattening of the tail reassured me that it was most likely an eel, or so I convinced myself. Swimming downstream in a large river always fills me with trepidation even more so when you can hear the roar of water downstream as we continued our exploration. The source of this sound was a massive gour dam filling the passage and the water being forced through a small hole in the calcite. Immediately downstream the current was strong to swim against so we found a devious traverse route along the wall. Ahead we were faced with more swimming and again the roar of another set of cascades. These cascades made a magnificent picture. A double cascade created again by a massive calcite dam. This provided a logical place to end the day. The following day saw an early start as Anette had to leave the jungle that afternoon and enthusiastically she was maximizing the full potential of caving time. The remainder of the team headed to the new upstream cave of Hang To Mo which was a magnificent entrance but sumped only a short way in. From the previous limit Anette and myself continued the swim downstream, passing a ‘duck’ we continued to swim further and further and still we swam until we finally reached the third calcite barrier. Here a massive boulder slope tumbled in from the left which was not pushed. More swimming led to another massive calcite barrier. Again the water crashed noisily down a 12 m waterfall to a pool below. To reach the pool required a climb where a small inlet passage joined the cave (this was not explored). A short distance forward the way was blocked by another calcite dam, to reach this required a high level traverse. The way on dropped steeply to the water below but this time there was no cascade and it appears to be a sump. This was not conclusively confirmed as it would require a line to descend the calcite barrier. It was time for Anette to leave, only now did we appreciate the length of the swim between the second and third calcite barriers. In the far distance we could make the lights of the others taking photos, for almost a kilometer we swam, Incredible!