Sacsayhuamán or Saksaywaman (from Quechua Saksay waman pukara,, lit. 'fortress of the royal falcon or hawk') is a citadel on the northern outskirts of the city of Cusco, Peru, the historic capital of the Inca Empire. The site is an important example of Inca architecture and sits at an altitude of 3,701 metres (12,142 ft).
An Inca ceremonial complex
The Spanish chroniclers recorded that within the Inca's oral history, the fortress was said to be built during the reign of Sapa Inca Pachacuti and his successors, Topa Inca Yupanqui and Huayna Capac. Dry stone walls constructed of huge stones were built on the site, with the workers carefully cutting the boulders to fit them together tightly without mortar. In 1983, Cusco and Sacsayhuamán together were designated as sites on the UNESCO World Heritage List, for international recognition and protection. The archeological site is now a tourist destination.
Fitted stone walls and terraces
Located on a steep hill that overlooks the city, the fortified complex has a wide view of the valley to the southeast. Archeological studies of surface collections of pottery at Sacsayhuamán indicate that the earliest occupation of the hilltop dates to about 900 CE. Traditions linking Cusco’s layout to the shape of a puma gave Sacsayhuamán a symbolic place above the city as well as a strategic position.
The Inca decided the "best head would be to make a fortress on a high plateau to the north of the city." During the 15th century, the Imperial Inca expanded on this settlement, building dry stone walls constructed of huge stones. The Inca ordered that the provinces should provide 20,000 men and that the villages should send the necessary provisions. If any fell sick, another labourer was to supply his place, and he was to return to his home.
But these Indians were not kept constantly at a work in progress. They laboured for a limited time, and were then relieved by others, so that they did not feel the demand on their services. There were 4,000 labourers whose duty it was to quarry and get out the stones; 6,000 conveyed them by means of great cables of leather and of cabuya to the works.
Transporting and shaping the blocks
Vince Lee is an author, architect and explorer who has been consulted on various ancient sites that moved large megaliths. He theorized that the blocks were put into place by carving them first and then lowering them into place. This would have involved doing precise carving ahead of time to create the tight joints that are made to fit into prepared pockets existing in the wall.
Then they would be towed up a ramp and above the wall where they would be placed on top of a stack of logs. Then the logs would be removed 1 at a time to lower the stones into place carefully. An experiment was done to see if this would work on a small scale; this accomplished limited success.
In the event that they were unable to obtain the tight joints the first time the Incas would also have been able to lift the stones back up to correct their mistakes. They were not able to obtain as much precision as the Incas but they theorized that with more practice they could have accomplished more precise joints and done it with larger stones. They also did several experiments in nearby Ollantaytambo to tow megalithic stones. This also led to limited success. They conducted one experiment where they tried to lower a 1 ton stone down a mountain.