These ruins were a 3 level fortification. Massive stones some as high as 17 feet and weighing 350 tons were perfectly aligned and fitted together to form the walls of the fortress. After the Spanish conquered the Incas here, many of the walls were destroyed and the stone was used to build churches and other structures in Cusco. We had a knowledgeable guide who pointed out many fine details of the construction. From the higher areas here there are great views of Cusco.