The trip to Dong Mu was to be a reconnaissance trip, we had looked at maps of the area and they showed what could be several sinks, the limestone in the area should be 900m deep so we could be in for a couple of deep caves!Well that was what we hoped for; unfortunately it didn’t turn out quite the way we hoped.
We were staying at Boa Lac and from here you have a choice of ways to get to Dong Mu, you can either walk 20km up a big hill carrying all your gear (ropes, bivi gear, caving gear and food) or you can travel by Jeep!(56km on rough roads, which takes about 5 hours)We went for the Jeep option.
Once we arrived in the village we had to find the President, who when we found him was more than helpful, unfortunately the information he gave us was not what we wanted to hear!There are no caves in the area.We showed him the map and asked if we could go look at a sink, he said “yes, but there’s nothing there!” a local man came with us to show us where it was, it turned out to be filled in, and the only consolation was that water does sink there in the wet season.
There was however a cave just outside the main village!Which we were shown to next, the locals had been clearing the hillside above it so we had a lot of brambles to move before a recce could be undertaken.Sweeney and Snablet obliged.After 20 minutes they surfaced, the prognosis was not inspiring.
More chats with locals and we found that we had looked in the only cave in the valley, which was a shame.Except there is one other cave just a short walk from the village, (this seems to be common in Vietnam, you ask if there are caves and get a reply of no! or there is one, and when you push the point a bit they sort of tell you about others, why?I don’t know, but that seems to be the way they do it) so we went to look. This new cave looked none too hopeful. It was a resurgence but it needed looking at, so I was dispatched into the void to see where it went, (Sweeney, Snablet and Mau started surveying) after 60m or so I came to a sump.
We were now staying in Dong Mu for the night; as it was to late too drive back to Boa Lac so we went back to the first cave to survey that one.
A scramble down the entrance led into a short passage and a left turn to another passage leading to a stream.Downstream went for 60m to a sump, whilst upstream was large and open.Upstream was 20m wide and 5m high, we followed this passage around a few bends for 250m or so, until we came to a boulder collapse We spent a while trying to find a way through it, in the end we managed to find 3 ways through to the same point which looked like we might need wetsuits.I went for it only to find out you didn’t!The passage continued for 200m until another boulder collapse, which was easily passed into a nice streamway, but time and lack of the right gear was against us, so we turned round and surfaced.At this point our problems started.It was dark outside and we didn’t have a clue how to get back to the village, it took us bout 30mins to negotiate the paddy fields, without help from the locals we would have been there all night!!
After a nights sleep in luxury!(Village hall floor) we left Dong Mu and went to Loung Coa, which again, on paper, looked promising!Well, on arrival we asked and were told of a cave an hour’s walk away.So we duly followed the local man and went to see.
Yep it was an hour’s walk but what he didn’t tell us was that it was uphill!About 340m vertically and a kilometre away.This put us at an altitude of about 1200m.Well there was a cave there; I went to recce it expecting to be heading downhill soon (how wrong was I).
From the entrance a short passage went left for 40m to daylight, right went 20m the to left into a large chamber (80m long 50m wide).At the bottom of this it hit a cross passage we turned left as it was BIG and looked good!This large passage continued for a couple of hundred metres until we came to a boulder choke that we couldn’t find a way through, the passage we had come down wasn’t well decorated, just large (30m wide by over 10m high).We had seen a passage off to the left on the way in so we continued our exploration down this.It turned right then left into a phreatic tube at an angle of about 50 degrees down and was around 50m long, at the bottom of this tube was a large cross passage, we turned right and were rewarded with 50m of passage which had some fine decorations at the end of it but no easy way on!Left looked more promising as it was larger, a short scramble down and we were away, but only for 20m as we came to a short pitch, we didn’t have any ladders or ropes with us so it remained undescended!Time, again, was against us so, we had to leave which was a shame, on the way out we looked at a short passage of the main passage; this only went for 30m into a chamber with no apparent way out.
Back to the surface, the mist had cleared and we got a fantastic view of the Loung Coa valley and the hill (mountain) we had climbed up!And were about to descend.
Back at the Jeeps our driver had chatted to locals and found resurgence for us, so we duly went with the man to look, it was a 60m rift to a sump, shame but there you go.
We left Loung Coa and on the way down we stopped several times to ask if there were any more caves in the area, each time getting the same answer, NO!We did, however, spot one at the side of the road, so with gear in hand, we ran excitedly across a field only to be disappointed as it was only 10m in length!With that, we set off back to Boa Lac and to report our findings to the rest of the group.