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.