What is Machu Picchu? Machu Picchu is an Incan city built between two peaks of the Andean mountains and has survived nearly 571 years. The architecture of this ancient city is certainly something to marvel at. The buildings are made of pure granite, cut from large granite blocks and pushed up the steep slope of the mountain. They were then fixed together using a technique called Idquo ashlar, where the stones are cut in precise shapes so that they can be fit together without the need for mortar.