This remarkable state of preservation of Machu Picchu, with its superb interlacing masonry, satisfies even the most demanding visitor. This Inca city, comprising and upper and lower section with hourses, temples, fountains, plazas and agricultural terraces, clings to a mountain ridge, linked by scores of stairways and paths, and watered by natural springs. No other civilizations has managed to assemble so many colossal stone blocks so seamlessly. Cut with stone or bronze tools, the edges of the stones were rubbed smooth until they merged together perfectly, like a jigsaw. Just how the Incas transported the granite and chiseled it from the mountain remains a talking point for scholars today.