Imagining the difficulty, the people went through to place such a rock to support their wall is amazing enough. When you take a closer look and see how intricately the stones were placed and fit together, you appreciate their stone cutting and architectural skills even more. With no mortar used, every stone was nevertheless placed in tight formation and in complicated patterns with no gaps or loose joints between them. The Spaniards would have been astounded at the incredible construction that they had never even seen back in Europe.
We still have written records of the impressions that they got of the Inca people. One came from Garcilaso de la Vega, who was half Inca and half European. In his early 20s, he moved to Spain from Peru and continued writing his journals. Unfortunately for history, the church and government were quite involved with the entire process of recording what the "heathens" in the new world could do. Many of the documents that this journalist and many others left behind had considerably racist overtones.
One common thread throughout these records included the fantastical idea that the Inca were not responsible for these megalithic walls at all. Instead, giants lived in the lands before the ordinary people came and put the stones in place. These were also supposedly the responsibility of a group of people called the Viracochans, about which not much is known. In truth, it seems that most of the megalithic architecture in the area did occur before the Inca people took control. They were conquerors of former civilizations and did not create the world that they then lived in. Yes, they did add their own distinct styles and architectural aspects to the cities, but they did not raise them from the ground up.