I'm going travelling through Latin America next month for 6 months and will be arriving in Arica or Iquique, Chile, at the end of January. I then want to cross to Salta in Argentina before heading down to BA and then Back across to Mendoza to cross back to Santiago. I can't seem to find much information about how easy or difficult the crossing from Calama-Salta is. Has anybody done this and could you let me know about the frequency of buses etc across the border? Any other tips for the route i've mentioned would be much appreciated too. Thanks.