Sacsayhuaman or Saksaywaman is one of the most incredible Inca ruins, located on the northern outskirts of the city of Cusco, Peru, which is the former capital of the Inca Empire.
What we can see now is only a quarter of the original complex because it covered a huge area and was built like a fortress that could house more than 10,000 men. The remains consist of the outer walls that are made of massive irregularly shaped boulders that fit together like a jigsaw puzzle without the aid or mortar. The space between the stones is so small that even a piece of paper cannot pass through them.
Circular foundations of three towers can be spotted on top of the walls. The biggest cornerstone stands 8.5 meters high, while the longest of the three walls is about 400 meters and stand 6 meters tall. One single boulder weighs 120 to 200 tons.
These ruins are believed to have been built by the Killke culture that occupied the region between 900 and 1200 AD.