The 21-hour bus ride from Arica cost $18 - less than a dollar an hour! My tush was paralyzed, but....You need ro acclimate to the 11,000+ foot altitude. The first night, my body, which had been in the shape of a bus seat for so long, was trying to get used to being upright and/or prone in bed. I kept feeling the need to breath deeply, waking up during the night to do so. Now I know why they say don't drink at high altitudes. I had wine with dinner the first night, and it went straight to a headache.