There are a number of things which are just impossible to find in the Bolivian Andes - and believe me, I tried. Actually, there are probably hundreds of things you can’t get, but since I never actually tried to get my mitts on a golden sickle, velvet painting of Ronald Reagan or neon plastic bucket and spade, I don’t feel qualified to comment on their availability.

So let me modify my original statement. There are many things you can get hold of if the money is right, but there are a whole bunch of things which are pretty much impossible to get, though the treasure hunt to find out might fool you into thinking that your prize lies just beyond the next teetering pile of red tape. Like shoes above a size six. Or a sieve. Or a pint of Boddingtons. Or a bicycle pump.

The absence of this last item infuriated me beyond all reason and measure. I had bought a ramshackle iron sit-up-and-beg type bike from a walnut-faced man in La Cancha market in Cochabamba. The bike was easily forty years old, and had no brakes to speak of and no gears whatsoever. The tough, thin saddle bit into me hard every time I tackled a pothole - which was often, because the roads of the town were pockmarked like the face of a character in a Guy Ritchie flick. But the Cochabamba valley was relatively flat, and I could get pretty much anywhere I needed to be in under half an hour, though I might not be able to sit down when I got there. Regardless, it suited me fine.

The only thing that stood between me and two-wheeled nirvana was the complete lack of bicycle pumps in the town. That is to say that there were pumps - huge industrial jets of high-pressure air - owned by the many mechanics in the town, and held on to with fierce protection. This meant that every time my tyres developed a puncture or went a bit flat - roughly once a day - I had to find a mechanic’s workshop (and there were many), and pay forty centavos (about 5p) for a quick top-up of air.

Being the independent type of woman I am, I tried on numerous occasions to find my own pump, but with no success. I hunted around the markets and found nothing. I appealed to local Americans, who looked at me blankly or with incredulity (”You ride a bike? Here? Are you nuts?”)I tried getting one sent over from home, but it got lost in the post. There just weren’t any - though there were thousands of bicycles in the town. This, I realised, was a brilliant ruse - a way for the mechanics to retain an effective stranglehold on the bike-users of Bolivia. But at 5p a day for the freedom a bike brings, was I going to complain? Not blooming likely.

Next up on Things Which Are Really Hard To Find In Bolivia: A Sieve