The ancient civilization that built the city of Machu Picchu is the Incas. This remarkable site, located in the Andes Mountains of Peru, was constructed in the 15th century during the height of the Inca Empire. Machu Picchu is often referred to as the "Lost City of the Incas" and is known for its sophisticated dry-stone construction, which has withstood earthquakes for centuries. The site served as a royal estate and was likely a religious retreat. The Incas were skilled in agriculture, engineering, and astronomy, and Machu Picchu remains a testament to their architectural and cultural achievements.