Following that fascinating but frustratingly brief stop, we headed back into the motor-boats for a tour of the spectacular Clear Water Cave and Cave of the Wind. Both a part of a very long underground river system, bearing the name of the former.
This is the Clear Water River, a deep and very fast flowing torrent that has carved out the spectacular multi-level caves here. Far above the course of the current river are signs of former alternative courses and the smoothed-rock evidence of what used to be waterfalls. The impression is of a three dimensional labyrinth with tunnels and arches, and vertical and horizontal passages way above and far below, but frequently linking in a giant wormhole.
After the caves, it was back into the boats for another push upstream. Fortunately the water level was slightly higher than usual, so we were spared the normal obligation to get out and push the boat over the shallower sections.
Day one and day three of the Pinnacles expedition start and end respectively with a 9km hike through the jungle along the upper stretch of the river which is too shallow for boats.
We arrived at Camp 5 early and had time for a swim in the river before our dinner of packet noodles and bed at about 9pm.
Up early the next morning for a 6.30am departure on what is touted to be an "extreme" climb up to The Pinnacles, reserved only for the very fit indeed. It was only a 2.4km journey, but included an altitude gain of 1200m over that distance, so promised to be very steep. At this point I was beginning to wonder about all the beers that I'd consumed since Moscow.
The Pinnacles team at Camp 5, 6.30am. How many will survive the day?
The trek began steep and only got steeper. By 900m one of our team unfortunately had to turn back due to asthma. The rest of us pushed onward and upward, sweat pouring off us. As well as rain gear, (useless as we were soaked anyway), and energy food, we each had three litres of water, half of which we left at the halfway point for the return. At the 2km point, with just four hundred meters to go, things started to get really tough. Where we had been scrambling over rocks, now there were ropes to assist us up almost vertical pitches of jagged karst. There were fourteen metal ladders to be climbed, the most vertiginous of which had now been bolted and cemented into place thankfully, but the rest were still tied to tree roots with frayed bits of twine.
At some points we were obliged to gingerly side-step across treacherously slippery horizontal metal grids, or simple flat iron bars suspended above moss-covered voids between tall rock blades.
As our guide suggested, this is probably the worst parachute drop-zone in the world. On a more serious note, because of their upwardly hostile formation, it is also completely impossible to land a helicopter anywhere near here, making medical evacuation an incredibly difficult (and expensive) job for several relaying pairs of strong and very brave local stretcher bearers. This is one of last places in the world where you'd want to break your leg, but also, one of the easiest to do exactly that.
Christian and myself relieved to make it to the top, but dreading the even more nerve wracking descent.
In the far background, beyond the Pinnacles, a patch of light green is the landing strip of Mulu airport.
The descent was indeed tortuous, but two of us made it down in a speedy two and half hours. Keeping up a faster pace, made it slightly less impactful on the knees, but we both nearly came a cropper with the added risk. Arriving back at Camp 5 before 2pm, we plunged our aching limbs into the cold river in an attempt to stall the inevitable aches.
We spent the remainder of the afternoon and evening at Camp 5. In theory we could have made it back to Park HQ on that same day, but we spent the allotted second night there and returned along the same 9km hike on the morning of day three instead.