Puka Pukara is only a few miles outside of Cuzco on the road to Pisac. This site was interesting in that we could walk "inside", meaning between the rocks. There is a lot left that was not uncovered or rebuilt. This site was small in size compared to Sacsayhuaman.
The rough limestone used to build this site has iron in it and is probably how the name Red Fort came about. It contained fountains and baths and many rooms and may have been a stopping place for travelers or a lodge for hunting. At least this is what we read.