It is the first fact mentioned by a homecoming traveler that there is a twelve-cornered stone in the Street of Triumph in Cuzco, and into and around each corner other stones are so perfectly fitted that a knife-blade cannot be inserted between them. That fact is perfectly true. So also is the fact that ancient Peruvians transported stones weighing tons with llamas and human beings as their only beasts of burden. They lifted them to great heights without machinery, cut them without steel implements, blasted them without gunpowder, and polished by rubbing them with other stones and bundles of rough grass. They had no resources in building but their own energy. The vast “stones were raised by social institutions, supplying want of instruments by numbers of people.” This world of ruins, comparable to Egypt, “is isolated in the region of the clouds.” Stupendous scenes upon these elevated plains were object lessons--nearness of gigantic peaks, appalling depth of chasms. The Incas learned much from nature: from salt-strewn deserts to lay waste their criminals’ property, sowing their fields with salt; from the sea, maker of terraces. They finished off the mountain-sides with small _andenes_, or hanging gardens, which received the flow of water bestowed by the Inca upon his subjects with every patch of ground. They brought loam from the jungle in baskets and created land upon bare rocks. Where opportunity offered, the terraces widened, following the natural excrescences of the mountain. And when nature failed to point lessons, models were provided by far-receding civilizations so remote that they almost seemed to have relapsed into the domain of nature. Each served as the foundation for the next, like the rhythmic life of the jungle. Ancient Peruvians hesitated at nothing. They built an artificial city on a high, cold, almost waterless, plain, with a palace for the Inca to visit in, a garrison for his protection, and magazines and granaries for his soldiers’ food. Countless royal palaces, too, their niches covered with plates of gold, and convents like the House of the Virgins of the Sun in Cuzco, were duplicated all over the empire for other wives of the Inca as he chose among them, “storehouses sheltering his tribute in women.” There were baths and fountains and places of pleasure and round stone _chulpas_, towers of the dead.