The great architectural achievement of the Inca civilization located in Peru is Machu Picchu. This 15th-century citadel, situated high in the Andes Mountains, exemplifies Inca engineering and ingenuity. It served as a royal estate and religious site and remains a symbol of Inca culture. The site features sophisticated agricultural terraces, intricate stone constructions, and significant religious temples. Its construction techniques, utilizing precisely cut stones without mortar, showcase the Incas' advanced understanding of architecture. Machu Picchu has become a UNESCO World Heritage Site and is a major tourist destination, representing the enduring legacy of the Inca Empire.