Geological analysis showed that the construction of the city of Machu-Picchu highly in the mountains was facilitated by existing cracks in local stones.
Inca builders skillfully used natural cracks in surrounding rocks / © Rualdo Menegat, GSA
The "uncomfortable" position of the city has other advantages. The same cracks in the surrounding rocks are sent to the surrounding agricultural grounds abundant threads of pure melt and rainwater from the top. And vice versa, during strong thunderstorms, quite frequent in this region, they allow streams to quickly go down, in valleys, without affecting the city. No wonder he worked safely for more than 500 years.