The last and next-to-last places I visited in South America were Pisac, an Inca remnant, and Ollantaytambo, the return point from my visit to indigenous communities. Ollantaytambo is generally hailed as the only place where the Inca were able to resist attacks from the Spanish. The Incas managed to lure them to this valley, rolled boulders down on them and used aqueducts to flood the valley, making it hard for the Spanish horses to find sufficient footing. Because of their horses, armor and guns, the Spaniards previously had been invincible.