Inca architecture was among the finest prehistoric architecture in the world. Examples can be seen in Cuzco
and Ollantaytambo, and of course here at Machu Picchu. The building style is characterized by exquisitely cut masonry, placed together completely without mortar. The raw material was granite, worked by stone and sand into irregular shapes that fit together like a gigantic puzzle. Some stones have as many as thirty facets worked into the surface, and as a result, the faces of the stone fit together so tightly that a needle won't fit between them.
More Inca Resources