This September a team of British and Irish cavers will take on an underground river in China's Sichuan Province in an attempt to complete a challenge which it started last year.
Time was the triumphant enemy when the China Caves Project team tackled the linked Great Crack and Great Doline caves in Sichuan, but this year we are determined to even the score.
The prospect of making the connection is as tantalising as ever, even though our survey data shows a 50 metre difference in elevation between the two underground sections, with their smooth walls and raging torrents.
When the connection is made, and we are confident that it will be, the traverse along the base of the Great Crack and through the entire cave system from sink to resurgence will surely prove to be a great adventure.
The British first tried their hands at caving in China 16 years ago and the practice has been accelerated by the gradual movement of the bamboo curtain in the 1980s. Prior to this we could only study maps and geology from afar and dream of what lay beyond our grasp.
China covers a vast geographical area and consequently boasts unrivalled ranges of both altitude and latitude. This coupled with a greater abundance of cave-bearing limestone rock than the rest of the world makes the country something of a Mecca for cave explorers.
A small group of British cavers visited China in 1985. Working alongside members of the geography department of Guizhou Normal University and the Guilin Karst Institute they explored and mapped caves in both Guizhou and Guilin provinces. This cooperation between Chinese geologists and British cavers has formed the basis of the China Caves Project. To date the team has fielded 12 major expeditions to the Hidden Kingdom and has never failed to uncover ever more spectacular cave systems.
The past three expeditions have concentrated on an area of limestone high above the Yangtze gorges in the Sichuan province of central southern China. Based in the small rural town of Xing Long, the team has been concentrating its efforts on the exploration of a system of caves associated with two of the geological wonders of the world.
The Great Crack runs for a distance of over six kilometres, an incredible gorge varying in width from only two to five metres at its top, yet more than 220 metres deep. Access to the base of the Crack and the traverse of it has required an exciting combination of abseiling, climbing, swimming and caving skills.
As the very first humans to enter this strange and remote place, we found a seemingly lifeless world lit only by a thin strip of light from far above. Bare walls scoured smooth by the force of water served to remind us of the powers that shape these unique karst landscapes. They also made us acutely aware of the risks of being hit by a flash flood -- a risk all too graphically demonstrated to us only a few days prior to our first exploration of the Great Crack.
In 1996 a team of four cavers entered a cave system located in the side of a dry riverbed upstream from the Crack. The team split into two, one pair surveying the upper reaches of the cave while the other team pushed on down into unknown territory. The first group successfully completed their task and surfaced after six hours underground to find a major thunderstorm in progress. With no way to warn their colleagues now far below they could only sit and wait with a watchful eye on the still dry river bed. After a nail-biting 14 hours the second team surfaced blissfully unaware of the storm having explored the cave 135 metres below the dry riverbed.
The storm continued throughout the night and the next morning the "dry" riverbed was found to be in full flight with the cave entrance and obviously the entire cave system several metres below the water level.
It was only when we abseiled into the far end of the Crack where it is at its deepest that we realised that the entire feature continues underground, forming its own spectacular cave. …