Looking down on Cusco.
Leading up to this trip, I was very nervous about how the altitude would affect me. So, I did the smart thing and obtained altitude sickness pills, Diamox, from a travel clinic prior to my trip. I was instructed to take the first pill 12 hours before my arrival in Cusco, and to continue taking one pill every 12 hours until they were gone. I believe there were around 8 to 10 pills total. I must say, the pills worked for me. I did feel very tired my first few days here, but that always happens when I travel, so I can't necessarily blame that on the altitude. I also had some shortness of breath when climbing stairs, so that probably was a direct affect of the altitude. I did not however feel nauseous or experience headaches, which is what I was especially worried about.