Incahuasi (6,641m) - Provincia de Catamarca, Argentina

This huge volcano, the 12th highest mountain in the Andes, lies just south of the paved road from Fiambala to Paso San Francisco, and as it is so accessible receives more ascents than most of the other 6,000ers in the area.

After taking 2 1/2 days to cycle up from Fiambala to Argentine immigration at Las Grutas we headed off the main road, cycling 2kms towards the mountain to some termas. After spending the night there we continued on a rough track for 9kms towards the mountain by which stage the surface was so bad that we decided it'd be quicker to leave the bikes and continue on foot.

The weather had been unsettled on our cycle up to Las Grutas, with lots of threatening looking clouds, and some thunderstorms at night. As we walked 4 hours from the track to a low camp at 4,600m, lots of ominous lenticularis clouds appeared to the east of the mountain. We probably should have turned back at this point (and would have done had we known what was to come), but as the weather was nice every morning we decided to continue. During the night there was a big storm a few kms away to the east.

The following day we continued, going between the dark volcancitos which lay between us and the mountain, before descending 50m to the usual base camp at 4,950m. The weather, which had been nice, took another turn for the worse, and as we climbed up the sandy NE gulley aiming to camp at the col at 5,700m, we were overtaken by a hail and lightning storm and spent half an hour crouching behind a rock waiting for it to pass. We were at 5,400m at this stage and when the weather improved, decided to stay here to camp. We were well acclimatized so didn't think we'd have any trouble summitting from this low down, and the weather remained bad up at the portezuelo so this seemed like the sensible thing to do. However, there was no flat ground around (apart from a couple of exposed spots that we didn't fancy camping on in case the lightning returned) so we spent 2 hours chipping a platform out of the ice in the gulley using rocks and some tent pegs. As there was no running water in the vicinity we melted the chippings to drink.

The weather was still overcast when we went to bed, but when we woke at 07:00 it was clear again. We set off just after 08:00 and followed the clear path for an hour to the portezuelo at 5,693m. There is meant to be water near here, though it wasn't that obvious to us as we walked past where this was. From the portezuelo the going became steeper, firstly up sandy/scree slopes, then up the rocky NE ridge to the right/north of the large penitente field. We had to use our hands at a few of the steeper sections on the ridge.

We emerged onto easier ground at 6,225m and from there the route to the summit was clear. We initially walked across a plateau, then headed between 2 penitente fields at 6,434m. The weather began deteriorating and we were walking through clouds for this section, with visibility often down to 100m. After passing through the penitente fields we climbed up the gentle slope to the summit (6,641m), arriving 4h45 after leaving camp. Here the weather was clear to the west, so we had views of the stunning Laguna Verde in Chile, and could just see El Fraile. Ojos, Walter Penck and Nacimiento were all obscured by cloud however. Unlike some of the other mountains in the area the summit is very obvious, even more so as it is marked by a 1m tall metal cross, and there is also a plaque left up there by the Reynoso family to a friend who died in the Peruvian mountains.

The weather was now looking pretty bad so we didn't stay long on the summit, then took the most direct route back to camp. Descending to where the streams emanating from the 2 penitente fields (we'd passed between on the climb) go off the edge of the plateau and following this gulley directly to camp. The first part was steep with loose rock, but after a while it became easier. The last few hundred metres were on sand and as we could tell a storm was coming we ran down these, arriving back at camp 1h45 after leaving the summit.

The next few hours were the scariest of our lives. The first storm duly arrived, but though our tent was pelted with hail, the lightning never came too close. A couple of hours later however and a second storm came very close, far too close for comfort. For an hour we sat squatting in our tent as every 5 seconds a lightning bolt struck the mountain. Hundreds of times we heard roars of thunder and we lost count of the number of times that the thunder arrived simultaneously with the lightning. It was terrifying. We were thankful that we'd put up the tent in the shallow gulley the day before, because if we'd been up on the portezuelo during this storm we would've been in a whole heap of trouble.

After the longest hour I can ever remember the storm finally passed and we were able to relax and lie down, which was very welcome as our feet had long gone dead. (If anyone else is unlucky enough to be caught in a tent in a storm, here's some advice as to what to do.)

During the night there was another big storm, but it wasn't too close, and in the morning (sunny again) we got the hell off the mountain. It was only 3 hours back to the bikes, the first part walking in 10cm deep snow that had fallen the night before. We were soon soaking in the termas again and spent the night at the refugio at Las Grutas. Much as we love the Andes this put us off for now, so we decided to change plans and leave climbing Veladero, Tortolas and Olivares, which we'd planned on climbing in the next month, for another time and head to the Argentine Pampa instead.

Some GPS points

Description	Lat	Long	Alt
Left bikes	26.96700 S	68.19588 W	4,060m
Low camp	26.99999 S	68.24476 W	4,622m
Usual basecamp	27.01368 S	68.26041 W	4,954m
High camp	27.02448 S	68.27058 W	5,401m
Usual high camp on col	27.03285 S	68.27296 W	5,693m
Top of NE ridge	27.03385 S	68.28124 W	6,225m
Between 2 penitente fields	27.03035 S	68.29048 W	6,434m
Incahuasi summit	27.03374 S	68.29663 W	6,641m
On direct route down to high camp	27.02904 S	68.28287 W	6,181m

Nacimiento (6,478m) - Provincia de Catamarca, Argentina

We'd seen this large volcano often on our walk in to El Arenal, and then again from the summits of Viento, Ojos, Medusa and Walter Penck, and as it was the last high mountain in the vicinity we had our hearts set on climbing it before walking back out to the road. From the other summits the mountain had always stood out, as it is a far darker colour than all its surroundings.

Our Andes guide, and all maps we'd seen had the northeast summit of the crater marked as the highest point, however we'd seen on Google Earth that the northwest summit, 1.2kms away was probably a few metres higher, so we decided that we should probably climb both just to be sure.

We found an excellent campsite near a penitentes field at 5,400m and set off at 09:30 the next morning after waiting for the wind to die down. The climb up a wide, shallow gulley which had the odd penitente field in it was pleasant, and as the gradient wasn't steep we found it easy enough despite this being the fifth 6,000er we were climbing in nine days.

At about 6,300m we came to the base of the northeast summit mound, where the going got steeper, and it took about half an hour to make our way up this (4 hours in total from camp) to the northeast summit. This measured 6,469m on my GPS (which was about 30m more than we were expecting, so not sure if my GPS was having an off day) and here we found a cairn and some testimonios. We didn't stay long though as it was windy.

We descended the ridge to a low point at 6,350m, then climbed up to the northwest summit, taking about 45 mins from summit to summit. This was steeper than getting to the northeast summit, but was still simple enough with trekking poles. This summit measured 6,478m on my GPS, so was the true summit, as Google Earth had said. I think it is far less often climbed than the northeast summit though as there was only a small cairn with two testimonios, from 1999 and 2003, under it. We left our own scribblings in the vitamin tube there, before descending in 2 hours to camp.

Some GPS points

Description	Lat	Long	Alt
Basecamp	27.25459 S	68.49768 W	5,408m
Nacimiento NE Summit	27.28055 S	68.51316 W	6,469m
Nacimiento NW Summit	27.28098 S	68.52445 W	6,478m

Cazadero / Walter Penck (6,684m) - Provincia de Catamarca, Argentina

This was our favourite mountain on our trip to the Puna. Seldom climbed despite the fact it is the 9th highest in the Andes it has a fascinating summit - a jumble of rocky pinnacles which look like some post-apocalyptic scene.

It was a nice 2 hour stroll from El Arenal to get to our basecamp at 5,700m on the northeast side of the mountain. Most of the climbing was done right at the beginning as we went up a small valley, then there is a 2-3km long plateau to cross to get to the base of a canaleta with a small stream in it next to which we pitched our tent.

In the morning we followed this canaleta up to a penitente field by a red coloured little lake at 5,980m, then headed a bit to the right on easy ground to make it to the large canaleta that comes down from between Cazadero's two highest peaks. We followed this, past a few penitentes fields but walking all on sand/rocks until we were near the shoulder between the main summit and the secondary hump to the SE. Here we turned right/NW up steep boulder slopes towards the summit. Most of the rocks/boulders are firmly in place, but a few are loose so we had to watch where we were treading.

When we made it to the summit area we spent a little while confused as to where the actual top was. Rocky pinnacles everywhere and it seemed like it might take a while to work out which was the highest. Fortunately, from the first one that Neil climbed up it was obvious which the highest was, so we were able to scramble up there and leave an old credit card in the plastic bag of testimonios.

There were views of Nacimiento to the south, Tres Cruces to the west, Ojos to the north and Incahuasi to the northeast, as well as of Pissis to the southwest and all the beautiful couloured lakes near it. We'd felt good on the climb and it took 4 1/2 hours to climb the 1,000 vertical metres from our basecamp to the summit. The descent was also nice and quick and in less than 2 hours we were packing up our tent and returning to the 'lowlands' at El Arenal.

Some GPS points

Description	Lat	Long	Alt
El Arenal south basecamp	27.15916 S	68.50412 W	5,496m
Cazadero/Walter Penck high camp	27.17818 S	68.53392 W	5,693m
Near red lake	27.18518 S	68.53726 W	5,983m
In canaleta	27.18821 S	68.54209 W	6,134m
Cazadero/Walter Penck Summit	27.19626 S	68.56070 W	6,684m

Cerro Medusa (6,144m) - Provincia de Catamarca, Argentina

This mountain is normally climbed as an acclimatization peak for Ojos del Salado which is only a few kilometres away to the west. We however climbed Volcan del Viento before Ojos, then stayed in the area and climbed Medusa after summitting Ojos.

It turned out to be the easiest 6,000er we have ever climbed from basecamp to summit, and indeed it must be one of the easiest in the world in that respect. Getting to basecamp at El Arenal is a bit of effort though, so all in all San Francisco at 6,018m just to the north is probably easier as you can can drive straight to the base of the mountain on the paved road that goes from Fiambala to Paso San Francisco.

From our basecamp behind a big boulder at El Arenal we climbed up the easy south ridge which goes directly to the summit. The climb is not sandy or on loose rock for the most part, meaning that there are very few sections where you are taking a step forward and then slipping back.

At the top there is a small crater with a tiny crater lake, and a cairn marking the summit. There are excellent views of Ojos and Muerto which are both very close, as well as of Incahuasi to the northeast. The climb took 2 hours, and the descent just over an hour, so even though we didn't begin climbing until after 09:00, we were back in time for lunch.

Some GPS points

Description	Lat	Long	Alt
El Arenal basecamp	27.14957 S	68.49919 W	5,513m
Medusa Summit	27.12713 S	68.48467 W	6,144m

Ojos del Salado (6,892m) - Provincia de Catamarca, Argentina

This is the highest volcano in the world, the highest mountain in Chile and the second highest mountain in South America. Before starting our trip it was one we thought we'd like to climb, and finally after 16 months out here we were in the right area in the right season to attempt it.

After meeting Lisandro from Rosario, and Arkaitz from Spain at Aguas Calientes a few days earlier we decided to team up and climb the mountain together. From El Arenal we followed the stream heading straight for the mountain and climbed for an hour or so up a valley. This was an ok route to go, though on the way out we walked down the ridge immediately to the south of the valley, and this would be a better and easier way to walk in.

After the valley opened up we came across a path, and we followed this past a few penitentes fields to a good high camp at the junction of two streams at 5,750m. We were planning on camping higher, but this was a good spot and as we were well acclimatized we didn't think we'd have any trouble climbing the remaining 1,150m the following day.

In the morning we set off at 05:00 and climbed for a few hours up the steep boulder slopes above camp. There was so little snow around that we could stay on rocks and sand and didn't have to put on our crampons to go up the snow fields. At about 6,400m we reached the bowl that contains the world's highest lake, and rounded this to the right. Heading directly from here to the summit looked too steep, so we traversed left under a large snow field, before climbing steeply again towards the summit.

At 6,800m we came across the remnants of a crashed helicopter on a small flat area (to add to the one we saw on Cerro Plata - when will these pilots learn?!) before climbing steeply again to the summit. The weather was perfect with no wind at all, so we stayed an hour, savouring being higher than we'd ever been before. There were big volcanoes in all directions, but all of them far far below.

Ojos has two summits only about 100m horizontally apart, but with a 40m vertical drop in between. We were on the eastern/Argentinian summit and resisted the temptation to climb to the western/Chilean summit even though at the time we were up there we thought it was a few cms higher. The day before our climb Jonathan and Chan, two students from the University of Alaska, had taken up a GPS capable of measuring altitudes extremely accurately and had told us that the climb down to the western summit was a bit 'sketchy'.

(When, a few months later, the numbers had been crunched the results showed that actually the eastern summit is 31cm higher, with an error of just 2cms. Both summits are 6,892m. For measuring the altitudes it's obvious which is the highest rock on the western summit, but the eastern summit is a jumble of loose rocks. The pair told us they placed the GPS on the highest rock which seemed to be attached to the mountain to get the reading on the eastern summit.)

As a result we didn't bother climbing down then up to the western summit, and after taking plenty of photos of the sweeping views we headed down. On the climb we'd moved far slower than we are used to as we were in a four, and near the top we were travelling at a snail's pace, arriving at the top 7 hours after leaving camp. The descent was much quicker though, and in 2 hours we were in our tent and had passed out.

On our return to Fiambala we thought about getting a bus to Mendoza then heading to try and climb Aconcagua, South America's highest peak. This is only about 60m higher than Ojos and as we're so well acclimatized we were pretty sure that as long as the weather was ok we would be able to make it to the summit. In the end however we decided against it for 2 reasons.

The first is cost. All mountains in Argentina are free to climb, except Aconcagua for which you need a permit. This year prices have doubled and in high season a permit for foreigners is 500GBP per person. We'd have to wait until mid February when this falls to 200GBP per person to be able to afford it.

The second is the number of people on the peak. The 15 mountains we've climbed this trip we've only had to share with 6 people with whom we weren't actually climbing - 4 on Lanin and 2 on Parinacota - and we quite like it this way. On Aconcagua we'd be guaranteed to see a lot lot more as there are probably 1,000 people on the mountain in the busy season. At the moment we don't fancy going and joining the long line of people to the top, though it's such a beautiful area around there that maybe we'll change out minds...

Some GPS points

Description	Lat	Long	Alt
El Arenal basecamp	27.14957 S	68.49919 W	5,513m
Enter valley	27.14813 S	68.50222 W	5,522m
Ojos high camp	27.13218 S	68.51915 W	5,748m
Ojos del Salado eastern summit	27.10982 S	68.54157 W	6,905m*

* This was the altitude my GPS gave me, but the correct altitude (of both the eastern summit we climbed, and the western summit more usually climbed from Chile) is 6,892m.

Volcan del Viento (6,028m) - Provincia de Catamarca, Argentina

We climbed this in a morning from a camp near Portezuelo Laguna Negra. This camp was closer to the summit of Viento as the crow flies than a camp at El Arenal would be, but wasn't really the best place to climb it from as it meant we had to cross over a number of valleys before finally being able to head up to the summit crater. It therefore took us 2h45 to climb, despite the summit being only 500m vertically above our camp.

The summit is on the eastern side of the crater, and it was suitably windy for the last 50m. This was the steepest part of the climb, and we had to go on all-fours for a bit when the big gusts hit. At the top there is a cairn with testimonios underneath (though not many as it is only infrequently climbed), and good views of Cazadero/Walter Penck and Nacimiento which are the closest two big mountains. We took a better route on the descent, staying high to avoid the valleys, though it still took 1h45 to make it back to camp.

Some GPS points

Description	Lat	Long	Alt
Our basecamp	27.15941 S	68.47213 W	5,541m
Volcan del Viento Summit	27.19119 S	68.47418 W	6,028m

Cazadero Grande to El Arenal loop - Catamarca, Argentina - January 2011

We did this high altitude trek in Catamarca to get to El Arenal which we used as a base to climb a few mountains. It'd be a nice 6-7 day loop to hike anyway even if you don't want to go climbing, and you can find water every day unlike in many places on the Puna. There are loads of high peaks in the area and plenty of weird and wonderfully couloured lakes - black, turquoise, dark blue, crimson. There are many vicuñas on the lower part of this circuit, but for the few days spent above 5,000m you are unlikely to see any signs of life at all.

We caught a lift in a 4x4 from Fiambala to the refugio at Cazadero Grande (on the main, paved highway), then the camioneta went off road and drove us 10kms to a partly derelict and very basic refugio at Quemadito. There is water here in the Rio Nacimiento, and we stayed the night.

The following day was a long one, even though we had mules to carry our bags, as we walked up river towards Aguas Calientes (4,200m). After 8kms we passed a small waterfall, and 7kms further on we turned up the Aguas Calientes valley, and away from the Rio Nacimiento, at Las Juntas. 6kms up this valley, near the source of the slightly warm spring at Aguas Calientes there is a sheltered cave and some places to camp out of the wind.

Next day we walked 15kms to Agua de Vicuña (4,950m). At first we wandered up some shallow quebradas that it'd be possible to go the wrong way in and waste a bit of time, but after this we were walking up a very gentle gradient on a wide open plain, heading just to the right of Volcan del Viento. Luckily there was little wind around or this wouldn't be much fun as there'd be lots of sand in the air. At Agua de Vicuña there was a small penitente field up a valley to the north, so we were able to get water before camping behind a boulder and stone wall that previous hikers had built.

The third day of our walk in was a short one - continuing up the valley and over the Portezuelo Laguna Negra (5,570m), from where we had views of the small, dark lake, just to the north of the pass, and also our first sighting of Ojos del Salado and Medusa. Our basecamp at El Arenal (5,500m) was about 4kms further on from the pass, in the direction of Ojos. To get there you have to cross over a few small ridges, so there is a bit of climbing and descending to do. El Arenal makes a good base from which to climb Medusa and Volcan del Viento, and is also a good place from which to set out to make higher camps on Ojos and Cazadero/Walter Penck.

After climbing some of the peaks in the area, we walked out by following the valley that runs between Volcan del Viento and Olmedo (the volcano on the southern flanks of Cazadero). It took a day (12kms) to get to a camp (5,400m) on the east side of Nacimiento. (You have to head west over a small ridge when you reach the flat pass south of Viento and Olmedo to get to the valley near Nacimiento. If you stick to the main valley this heads back down to Aguas Calientes.) Then it was a further day to walk the 14kms back to the Rio Nacimiento and then 9kms following this to get back down to Las Juntas. From here to the road was nearly 30kms, and was a long day with heavy packs.

Some GPS points

Description	Lat	Long	Alt
Cazadero Grande Refugio	27.42016 S	68.13098 W	3,462m
Quemadito	27.37242 S	68.22502 W	3,650m
Las Juntas (go R for Aguas Calientes)	27.34508 S	68.34022 W	3,954m
Aguas Calientes	27.30501 S	68.35151 W	4,196m
Enter Quebrada	27.28029 S	68.36634 W	4,268m
Take quebrada on R	27.27002 S	68.37889 W	4,331m
Go L, straight at V. del Viento	27.25560 S	68.38281 W	4,388m
Climb up ridge to R, onto plain	27.24955 S	68.38825 W	4,481m
Leave plain, enter quebrada	27.22489 S	68.41347 W	4,664m
Agua de Vicuña	27.19793 S	68.43022 W	4,944m
Portezuelo Laguna Negra	27.16523 S	68.46047 W	5,572m
Good sheltered camp spot	27.15941 S	68.47213 W	5,541m
El Arenal camp	27.14957 S	68.49919 W	5,513m
Flat pass (head R over ridge towards Nacimiento)	27.22066 S	68.48526 W	5,331m
Join Rio Nacimiento	27.30758 S	68.41042 W	4,349m