From Santiago we took a 22 hour bus to Calama. The trip should have been 20 hours, but the bus broke down adding another 2 hours to our already long ride. The Bolivian Consulate in Santiago ran out of visas (the actual sticker that goes into the passport), so we headed up to Calama to get our visa. Obtaining the visa turned out to be a pain, and we later learned that you can bypass the system by booking a Uyuni tour, and the tour operators will get you the visa at the border. I wish we knew that before we went through all the trouble.