Havingcompleted the main objectives we had in Cao Bang, one outstanding issue remained. We wanted to check out a sink/resurgence system noted by Carl Maxon on his 1996 visit to Cao Bang. With this in mind, we made a slight detour from the usual route to Hanoi .
Carl’s resurgence was supposedly located by a particular kilometre marker post. The area did indeed look very promisingand we soon located the specified post. The resurgence nearby proved something of a disappointment, given that it would have taken the thinnest of Yorkshire Dales thin men to pass through the tiny muddy slot. The more plump members of the team (i.e. all of us) decided that we would not let Carl forget our wasted trip in a hurry.
Meanwhile, Mr My was doing what he does best – chatting up the local women. He soon returned with tales of a real cave. Unfortunately, most of the survey gear had by this stage departed towards our next point of interest in one of the other jeeps. With a set of Suuntos, a biro and the frontispiece of someone’s paperback, plus the unused pages of Martin’s passport as backup, we went in search of measurable caverns.
Two local boys accompanied us into the cave, passing on useful tips like “No not that way, it chokes” which we studiously ignored until the passage actually did choke. A scalloped streamway was followed for a couple of hundred metres in quite a sporting fashion – especially for the boys in flip flops or bare feet! The eldest of our companions told us the streamway dropped into a muddy V-shaped passage and then became full of water. We were soon walking along the bottom in the base of the V and a final climb down led to a large inlet sump. Clearly the people around these parts are not averse to a bit of darkness!
Returning towards the entrance, the boys pointed us towards a side passage. By this stage we had no hesitation in believing them. With the only last corner of the paperback remaining, it was looking like Martin’s passport was going to get some addition which wouldn’t necessarily meet with the approval of H.M. Government! However, a climb up beyond some interesting shingle-filled phreatic tubes posed more of a problem than we wished to negotiate at this stage. Just over an hour had netted us 511m of cave (none of it original!) and a good lead remained.
The next part of the journey took us through yet more limestone scenery which gave the impression of containing plenty of cave. Travelling along by a medium sized river, we chatted away until suddenly the river disappeared. Back-tracking quickly, the reason for the disappearance became apparent – a rather large rift swallowing all the water. We were already late. It would soon be dark. The drivers would get all grumpy again. What the hell, it was far too big a lead not to check out!
A few kilometres further on, we looked back towards the valley below the sink we had just checked and were astonished to see a HUGE entrance. Expletives were duly exchanged and plans to delay departure to Quang Binh discussed. It was too late. The train tickets had been booked and paid for. The resurgence would have to wait…