R-O-C-K (very ancient rock)

What is this? Limestone. What is limestone? It is a rock. R-O-C-K. Do not forget. Why is there no no roof here? The Incas would look up at Venus. And what else? Mars. And what else? The stars. S-T-A-R-S. This was the rhetorical question-spelling bee-style tour my Sacred Valley tour guide thought was the best way to make ancient Incan history come alive to foreigners. I did not learn that the terraces, the the ones in Pisac below, were built by the Incas to create mico-climates in order to grow a variety of crops, and that is one of the reasons they have something like 80 varities of potatoes in Peru. I was told the terraces were for erosion and decoratin, which is partially true, but not the coolest answer. I learned alot of neat things about the Incas later in Machu Picchu.