La Tren a las Nubes (The train to the clouds) originally ran to the Chilean border but now runs very erratic passenger services from Salta into the mountains. Typically, it was not running while we were there. So we took an excursion to follow the train's route up to the last station in the small town of San Antonio de las Cobres. The line itself was very difficult to build through extremely inhospitable terrain and took 23 years to complete. It relied totally on manual labour because no machinery could be brought into the area. Of the one thousand, mostly Bolivian and Chilean, workers employed, over 100 were killed during the construction and buried in small cemeteries beside the track. The designer and chief engineer now has the district and a small town named after him. One of his collaborators was Gustaf Eiffel (yes that one!) who designed the viaducts.

We went on our journey by 4x4 with Gabriel, our driver and guide from the last trip we made. We were joined by Claudia and Martin, a young couple from BsAs who were actually on their honeymoon (an interesting near coincidence as Jen's sister Jo was marrying Rob in Retford on the same day). Near to the beginning of the journey we stopped off to look at the old steam engine, sadly now only a monument to past glories. We were disappointed there was no Leeds nameplate as we have found on several on old engines.

The road that we followed through La Quebrada del Toro (valley of the bull) sticks close to the line but because of the steep ascents, the train loops and weaves around, at times even reversing back on itself. As a result we were frequently crossing and recrossing the track and got lots of good views of the many tunnels, bridges and viaducts. We've remarked in the past that great train journeys are frequently best seen from a hillside beside the track rather than on the train itself! We paused to walk onto the longest viaduct, a strange experience for those of us brought up with England's fenced off railways. A little later we caught up with a train actually running on the track. Although there are few passenger services, goods trains still run at variable intervals. This one was an Argentine diesel moving very slowly and pulling assorted cargoes including some earth movers, a fuel tanker and a couple of box cars. Later one of the men on the train said that it takes them about 8 hours to make the same journey we had made.

We stopped on the way to visit the ruined city near the present pueblo of Santa Rosa de Tastil at a height of 3110 metres. This pre-Incan city is believed to have been populated around 1360 and held 3000 people at its peak. It was probably constructed as a defensive position as it stands alone and has fine views over the valleys to the next peaks. The people erected stone buildings on a series of roads and squares over a wide area and farmed the steep slopes by constructing terraces and channelling water. However, there are no records to fall back on so nobody is clear just why they seem to have deserted the spot leaving so much behind. Even now you can just look down and find shards of pottery on the ground!

The rise through stunning scenery was really breathtaking. All around us were steep slopes, often formed into strange shapes by erosion over the years. We kept going up until we reached 4080 metres above sea level, the highest point of our journey. At this stage we dropped slightly and entered the puna, a huge area of flatland above 3000 metres and chiefly desert. Before us were the Andes proper, with several peaks at around the 6000 metre mark. In the distance we could see the white shimmer of the Salinos Grandes (salt plains) but we had chosen not to go on there because we have scheduled a visit to the considerably larger salt plains in Uyuni, Bolivia in a month or so.

The end of the line comes with the little town of San Antonio de Los Cobres, named after the copper that is mined there. Most of the town consists of the small adobe houses one would expect in this area. However there was also an estate of smart concrete houses recently built to house military personnel stationed there to search for drugs coming over the nearby Chilean and Bolivian borders. Although mining still goes on here, the town has seen better days and would have little to detain the tourist if the station were not there. After lunch in the town, we caught up with the goods train we had seen earlier and looked around the old station building where a few period features have been retained.

As well as stunning scenery, this was a great journey for seeing wildlife. We managed to see three of the four kinds of similar animals of the mountains; llamas, vicunas and guanacas (just the alpacas missing). Several times we saw condors sweeping high in the sky but you'll just have to take our word for it because they were very high and just specks on the pictures!

As we approached Salta on our return trip we could see dark skies and rain, although we had none of it. Sure enough we got back to find the streets flooded, sometimes to a depth of about 60cm and the wisdom of having a 4x4 was again apparent! Gabriel said that this was normal if there was more than a couple of hours of rain, wasn't it like that in England? He was surprised when I said that although flooding does happen, it is actually quite rare.