Susan, I agree wtih Marcie. We stayed overnight at the Sheraton & spent 2 full days at Iguaso.

It is Cuzco that is the highest altitude. Like Doug, we stayed at the Monesterio. Some of the rooms have piped in oxygen that you have to request. In the other rooms you can order an oxygen canister. One member of our group drank so much coca tea (over 10 days) that he got sick. My high altitude sickness was mostly insomina & I deny being irritable. One couple took medicine but they said it made them "tingly."