【明報專訊】Approaching the three-day Atacama crossing from Chile to Bolivia (玻利維亞), I was undoubtedly incredibly excited yet slightly anxious due to the high altitudes (海拔) and sub-zero temperatures that were about to hit us. Raising up to 5,500 metres above sea level (pretty much on the same altitude as the Mount Everest base camp), and stretching some 1,000 kilometres over two countries, the Atacama Desert is, according to NASA and National Geographic, the driest desert in the world.