On the genius of Inca engineers

This is the Zona Arqueologica Moray, sitting at about 11500 feet and about an hour northwest from Cusco in the Sacred Valley of the Incas. I've got my head in the photo in an effort to give a sense of scale but it's not a great visual effect since I'm way up on a bluff overlooking the place and the whole site is massive.  It consists in concentric terraces that go down, down, down into a deep depression of land that is sheltered on the windward side by a tall rock face.  

Moray is pretty much my favorite site in the Sacred Valley region.  There are loads of other structures and artifacts remaining nearby from the Inca period (15th-16th centuries).  But this one kinda blows my mind.  It seems to have been an agricultural lab. In the bottom photo, you can see the peaks of the Andes in the near distance.  On the other side of those peaks:  a tropical ecosystem, filled with all manner of fruits, veggies, tubers, corns, squashes....stuff that doesn't necessarily thrive at 11500 feet.  So these genius Inca ag engineers created this kinda open-air hothouse to train plant species up to elevation hardiness.  Archaeologists have discovered seeds and plant matter along those terraces, and have concluded that the Incas would bring, say, a bunch of corn seeds from the jungle side of the Andes and plant them in the bottommost level of the lab.  Because of sun angles and wind/weather protection, that bottommost level is substantially warmer than the higher levels, and is also the endpoint of irrigation drainage.  So: hot and humid down there, like a jungle. The corn would grow down in there and get accustomed to the climate over a season or two, and then they'd move the corn crop up just one level, getting the plants used to that one level less jungly.  And so on, over a couple of decades, until the corn was growing on the top level, in the standard 11500-foot weather/climate.  In this fashion, the Incas trained up a rich variety of food crops that didn't naturally flourish in the Andes.  

(Look at these cool protruding-rock stairs built into the terraces)

I love everything about this centuries-old ag lab, but especially the foresight and patience of it all.