Uncharted regions have fascinated explorers and adventurers for as long as humans have been blessed with curiosity. However, in the age of Google Earth, and as mapping abilities and global communications systems have improved, blank areas on the map have become few and far between.

In September, a team of six mountaineers embarked on a mission to explore one of these last frontiers: a mountain range in northwestern Sichuan province - the Gangga massif, which, due to political restrictions and the complexity of access, had been until recently totally off-limits.

Here is what happened, as documented in the journal of Hong Kong-based Austrian mountaineer Paul Niel.

Day 1 (Chengdu, September 16) The adventure has finally started - my journey from Hong Kong to Chengdu was short; it took the taxi driver almost longer to find my hotel. Here I meet up with Ed Hannam, the leader of our team. We got to know each other a year ago during a daring winter ascent of Mount Fuji, Japan's highest mountain. There, in a windy ice-cold tent at night, the idea for an expedition to one of the last unexplored corners of China was born. In Chengdu, we are joined by Judith Fall and Gerald Boess, climbing friends from Austria, as well as Australians Dan Da Silva and Rob Baker. Together we are a strong team, ready to follow in the footsteps of ancient explorers.

Day 6 (Garzi, September 21) After a bumpy two-day ride in a minibus loaded up to the roof, over partially mudslide-covered roads, we have finally reached Garzi, a small provincial town by the Yalong River. In addition to our team of six climbers, we have local support on board. Alex, a student from Chengdu, has joined us as a translator, together with Pen, who will be our cook in base camp.

Just as we reach the top of the last mountain pass, Ed shouts, "That's it, there on the horizon, those are our mountains, that's the Gangga!" In the distance we spot an array of rocky spikes, some of them covered with snowcaps, too distant to identify features but the peaks look impressive nevertheless. Our permit lists our goal as "Mount Wunjiang - 5,429 metres", but, Alex explains, this is just a placeholder name the authorities use for unnamed mountains.

To our knowledge, nobody has ever explored the region or even tried to climb it - all the surrounding valleys are untouched.

Day 7 (Garzi, September 22) It is not often that one mistakenly walks into a gold mine. I must have looked quite dumbfounded this morning when I suddenly stood at the entrance of a rather large tunnel. Confused, I consulted my Google Earth printout, but nothing was to be seen. The mine's owner made it clear that he wasn't at all happy to have a group of mountaineers walking past his mine, which meant our planned route towards the massif, from the north, was unusable.

After a lengthy group meeting we decide to build base camp in the southwestern foothills of the massif, undisturbed, all sides engulfed by steep slopes and rock faces, all of them unexplored.

The afternoon brings me a personal success - after several hours of searching I find an old Tibetan lady who helps in my quest for a name for our peak. With a wide grin she points her arm towards the summit: "Zhouda!"

Day 9 (Base Camp, September 24) The joy of being dropped just a mere half mile from our base campsite by minibus a few days earlier was lessened when we realised a fierce river had blocked our way to the pro-posed site. Ed and Dan built a small rope traverse, which allowed the heavy bags containing tents, food and kit to glide over the river.

It was worth the effort - now that all the tents are standing, the place is really peaceful and quiet. The spot has good sunlight for most of the day and is sheltered from the wind. Alex and Pen cook up a great local meal: parts of pig and beef, local vegetables and tons of chillies converted into a great spicy Sichuan dish. Right behind our tents, a steep grass and scree slope points the way towards the higher reaches of Zhouda. Somewhere up there in the clouds is its southwest face.

Having established base camp we set out to climb higher and set up a high camp that will serve as an advanced base for a summit push and make it simpler to explore the surrounding valleys. With backpacks full of tents, sleeping bags and several days of food and water, we scramble up the slope. The heavy bags turn the ascent into torture - loose rocks on the scree slope mean that with every two steps upward I am sliding one backward. I am short of breath as I am not yet acclimatised and a perfect blue sky means the sun is baking me in my thermo clothing. We decide to pitch high camp on the bottom of a very large scree field, directly in sight of the steep and impressive west face. The spot is scenic but is situated on a few large rocks - despite a concerted effort by the whole team we cannot turn it into a flat surface. I can feel every rock under my sleeping bag - I am sure it will be anything but a comfortable night, given that Rob and I are camping in a tent that has barely space for one.

Through binoculars we have identified two possible routes to the top - straight through the face on a challenging rock route or on the side through a promising snow gully. The plan is to attack with a small team on either of the two options early tomorrow morning. That is, if the weather holds, which is not certain right now. Snowflakes have been falling.

Day 10 (High Camp, September 25) By the time I wake up in the morning, everything is covered under a white coat of snow. We decide to retreat downwards for lunch in base camp, where Pen tries to lift our spirits with spicy stew and a beer. It seems to work and by late afternoon Ed has convinced the team to give it another go tomorrow morning, this time straight from base camp. Alarm clocks are set for 4.30am.

Day 11 (Base Camp, September 26) We make good progress in the cold early hours. By mid-morning we are back at high camp and from here we start to slog through another long, steep scree slope (I start to think this mountain consists only of rubble stones). Our plan is to move through the previously identified gully, as the rock face is covered in ice from the previous day.

The going is slow - my body is still not fully adapted to the altitude, a process that usually takes me a week. In addition, the steep scree is turning out to be very dangerous. Every footstep runs the risk of triggering a rock avalanche, every move is done on eggshells. Pretty soon we rope up, Ed is taking the lead, climbing the first few pitches of the steep snow slope. Small streams of ice water are trickling down as the midday sun starts to melt the ice. Steadily we climb higher, with the surrounding peaks slowly vanishing below us. I am so focused that I only register the oncoming thick clouds when they start to engulf the mountain. Suddenly the booming sound of thunder fills the air - the weather has definitely changed. With the temperature dropping quickly, I can feel my fingers and toes starting to get very cold. Our climb has slowed down and ultimately grinds to a halt. We stand in a wedge between two steep rocks and an overhanging wall of ice. Rob is making a desperate dash to scale the frozen ice, but it seems to be a dead end - the ice is too rotten to put any protective devices into it, pushing on is too dangerous.

I am not sure how far it is to the top - 150 to 200 metres further? The weather makes the decision for us. It's already past 6pm and darkness will soon fall; we are more than 13 hours under way and still have a long, cold way down ahead of us - Retreat! Rappelling down is a slow process - Ed and me are the last ones. In heavy snowfall and with frozen fingers, it's quite scary, my tiny headlamp the only light in the pitch darkness that soon engulfs us.

When we hit the tents shortly before midnight we are all exhausted - Gerald's beard is frozen up and I can barely feel my toes. The weather on this mountain has beaten us again. Maybe it's time to look for a new approach.

Day 14 (High Camp, September 29) Finally the sun is shining again. The past days were a frustrating wait for better weather, which I spent mostly reading books. We also made an ill-fated attempt to bribe a mine official to allow us onto the north side of the mountain - to no avail. So we are heading back up - Dan brought up the idea of examining the slopes above high camp a bit further and in the absence of a better plan the rest of us readily agree. The great blue sky is shining down on us as we scale a never-ending amount of boulders and, instead of hitting the end of the valley, we soon find ourselves in a huge amphitheatre of peaks, spires, pinnacles and steep ice slopes. I am in awe - humbled by the beauty of nature and the special feeling of being the first to take a look at this untouched part of our planet. This is how the early explorers must have felt when they came to realise the vastness of the world.

Best of all, Rob spots a possible route through one of the rock faces, a path that could lead us to the summit tomorrow. To celebrate the discovery, I have a bigger than usual meal - beef jerky, freeze-dried noodles followed by a pack of M&Ms. As I cuddle into my sleeping bag, spirits are higher than ever.

Day 15 (High Camp, September 30) I am ready, packed, dressed and out of the tent by 5am. I have even allowed myself a second bag of instant porridge. The sky looks clear as we approach the rock face in the amphitheatre. The only thing that bothers me is the wind. We are quick and the sun hasn't even risen over the horizon when Dan starts leading the first pitch. Just as he gets out of sight, the rock fall starts - first only small ones, which I think are coming from Dan, then bigger ones. Like grenades I can hear them whistling through the sky and hitting the rock and snow around us. The strong wind, combined with the sunshine, is blowing all the loose rubble off the rock face and straight onto us. I feel a first then a second impact on my helmet. The situation starts to get more and more uncomfortable - boom! - a rock the size of a football makes impact a mere half a metre from me.

"That's wrong! We need to get out of here," Ed is shouting over to me. In Judith and Gerald's faces, I can also spot a bit of worry. It seems to be only a matter of time until one of us gets hit - that would be very bad news, with the nearest hospital being several days' journey away.

We quickly come to the only logical conclusion - this route is just too dangerous today, the sun and wind making it too unstable. By late morning, we are back in high camp. Utterly frustrated, Ed and Rob retreat straight back to base camp, convinced that upcoming bad weather would render a further stay in high camp useless. This morning I was convinced we would make it to the summit today and now I am back in base camp before lunch - what frustration! I have reached my low point of the whole expedition so far. Third attempt, third failure!

Day 18 (Base Camp, October 3) The past few days the whole team has been stuck in base camp. The weather has turned significantly colder and the surrounding mountains are turning whiter - winter seems to have come. Pen has tried his best to make us feel better. He even found a crate of beer somewhere. But the frustration about the unpredictable weather and the unsuccessful attempts is sinking in. As the days are ticking away and our food reserves are running low, we decide to make a final attempt - back again into our snow gully with our last hope.

We are starting early in the bitter, cold darkness. I can feel my improved acclimatisation with every step and by late morning we have made good progress into the gully. The conditions are significantly better - the cold has made the snow more compact, allowing us to progress much quicker. By lunchtime we reach the ice overhang - our high point from last time. In a few impressive moves Rob manages to climb to the top, reaching the next step. As Judith and I are following we are getting showered in ice that's falling from further up. My ears are ringing with every direct hit onto my helmet.

Just when I want to shout out one hits me in the face, leaving me with a bloody nose and a split lip - it could have been way worse. The route increases in difficulty, one steep, overhanging step follows the other. Meanwhile a light snow-fall has started - the dark clouds and falling temperatures are indicating much worse to come. The gully is getting steeper and our progress slower, until we literally hit the wall - our route suddenly comes to an end in an overhanging rock wall. My altimeter shows 5,340 metres, we are less then 100 metres from the summit. So close, nevertheless, unreachable. There is no time to search for an alternative route as the snowfall has turned into a snowstorm. Small spindrift avalanches are starting to form, turning the gully into a trap. Again, we are back to nerve-racking rappelling in dreadful conditions - at times the snow coming down the mountain threatens to pull me off my feet and bury me. By the time we hit our tents I am soaked, exhausted and freezing cold.

Day 19 (High Camp, October 4) I wake up feeling empty, thoroughly exhausted and tired. I barely slept in the empty cramped space of our tiny tent, everything being wet around me. Today is our last possible climbing day, tomorrow we are getting picked up and we still need to put down base camp, pack everything up and carry it through the river. An attempt to the top is out of the question - too much snow has fallen, but Judith and Gerald are keen to explore a little bit more of the mountain. Minimally equipped, the three of us set out, but we soon realise that almost all possible slopes are too dangerous after last night's snowfall. Only a couloir towards the far side of the amphitheatre looks to offer climbable conditions. With every step I can feel the exhaustion of the previous days in my legs. We don't have much time as big, dark thunder clouds are starting to build in the sky. Yet again the mountain seems to want us off its slopes. We touch the top of the ridge, fix some Tibetan prayer flags and leave some sweets as presents for the mountain gods.

It's a consoling finish, having had another look at these pristine valleys and having managed to explore another puzzle piece in this sheer, endless massif.

OUR EXPEDITION hasn't resulted in a summit - the unpredictable weather, bad rock and snow conditions made the path to the top too dangerous and difficult. I cannot rid myself of the feeling that Zhouda didn't want us on its top - this time …

What we are bringing back are precious observations, newly discovered valleys and peaks and a vast collection of information about the region.

Most importantly, despite the conditions, the team made it back in one piece, holding with a phrase coined by Edmund Hillary, who was the first to scale Mount Everest: "Getting to the summit is optional, getting down is mandatory."

Social climber

"I grew up in the Austrian Prealps and my parents took me to the mountains from a very early stage," says Paul Niel, who describes himself as a social entrepreneur and "future thinker". "I never lost the desire to go out into nature and have an adventure."

Those adventures have included climbing the "seven summits", the highest peaks on each continent, and becoming one of only a handful of mountaineers to have scaled two 8,000-metre peaks (Everest and Lhotse) within 24 hours.

Niel moved to Hong Kong 3-1⁄2 years ago, for a job in finance. But when he left the industry, the Austrian saw no reason to leave the city.

Hong Kong is "the best combination of outdoors and city that I know", says Niel, who lives in Chai Wan, which affords him the "opportunity to run the Dragon's Back every morning".

He now works with and invests in social start-ups ("companies that are not just maximising profit but also have a social mission"). He is co-founder of Peared, a lifestyle company for older adults, and Luxarity, a Hong Kong-based enterprise with a mission to upcycle luxury fashion.

As well as working with charities in Nepal and Hong Kong, Niel is the local ambassador for the Singularity University, an unaccredited teaching organisation based in America's Silicon Valley whose mission is to "educate, inspire and empower leaders to apply exponential technologies to address humanity's grand challenges".

Mark Footer