© Sebastien LAPEYRERE ; Machu Picchu ( Peru) November, 23rd 2015; Machu Picchu archaeological site . The ruins of the Inca citadel of 15th century stands at 2340 m altitude on a narrow rocky ridge above the Urubamba River. Composed of administrative , political and religious center dominated at agricultural terraces, astronomy observatory, temples and religious buildings, industrial workshops she would was built by the Inca king Pachacútec