Step 1 : Introduction to the question "what civilization is believed to have built machu picchu?"
Machu Picchu is a 15th-century Inca citadel situated on a mountain ridge 2,430 metres (7,970 ft) above sea level. It is located in the Cusco Region, Urubamba Province, Machupicchu District in Peru, above the Sacred Valley, which is 80 kilometres (50 mi) northwest of Cuzco and through which the Urubamba River flows.
