Abra Pirhuayani: 4,725 msl (~15,501 ft asl) – Leaving the Peruvian Amazon rainforest can be done in numerous ways, but most people stick to either flying out or driving out. Since I was there for research, I stuck with driving out too – hauling out a quarter ton of rocks is not cheap by plane. The 9 hour drive from Mazuko to Cusco is not a punishment however, but a truly impressing journey from one of the hottest and most humid areas in the planet, to snowcapped peaks and oxygen scarcity in a matter of mere hours. The highest pass on this whole journey is depicted here, Abra Pirhuayani, higher than any mountain in the lower 48 States. And that is just the pass, the mountains extend up to almost 6,000 msl! Despite being almost on the equator, there are year-round glaciers on these mountains, quite the contrast from the hordes of sandflies and mosquitoes from just a few hours earlier! After this, the road gently goes downhill again until you hit Cusco after another few hours driving through one of the most inhospitable and beautiful landscapes one can imagine. A truly humbling journey, for  both the impressive display of force by nature and for the adaptability of human life.