A little farther up the stream one passes through a massive megalithic gateway and finds one's self in the presence of the astounding gray-blue Cyclopean walls of Sacsahuaman, described in "Across South America." Here the ancient builders constructed three great terraces, which extend one above another for a third of a mile across the hill between two deep gulches. The lowest terrace of the "fortress" is faced with colossal boulders, many of which weigh ten tons and some weigh more than twenty tons, yet all are fitted together with the utmost precision. I have visited Sacsahuaman repeatedly. Each time it invariably overwhelms and astounds. To a superstitious Indian who sees these walls for the first time, they must seem to have been built by gods. About a mile northeast of Sacsahuaman are several small artificial hills, partly covered with vegetation, which seem to be composed entirely of gray-blue rock chips--chips from the great limestone blocks quarried here for the "fortress" and later conveyed with the utmost pains down to Sacsahuaman. They represent the labor of countless thousands of quarrymen. Even in modern times, with steam drills, explosives, steel tools, and light railways, these hills would be noteworthy, but when one pauses to consider that none of these mechanical devices were known to the ancient stonemasons and that these mountains of stone chips were made with stone tools and were all carried from the quarries by hand, it fairly staggers the imagination. The ruins of Sacsahuaman represent not only an incredible amount of human labor, but also a very remarkable governmental organization. That thousands of people could have been spared from agricultural pursuits for so long a time as was necessary to extract the blocks from the quarries, hew them to the required shapes, transport them several miles over rough country, and bond them together in such an intricate manner, means that the leaders had the brains and ability to organize and arrange the affairs of a very large population. Such a folk could hardly have spent much time in drilling or preparing for warfare. Their building operations required infinite pains, endless time, and devoted skill. Such qualities could hardly have been called forth, even by powerful monarchs, had not the results been pleasing to the great majority of their people, people who were primarily agriculturists. They had learned to avert hunger and famine by relying on carefully built, stone-faced terraces, which would prevent their fields being carried off and spread over the plains of the Amazon. It seems to me possible that Sacsahuaman was built in accordance with their desires to please their gods. Is it not reasonable to suppose that a people to whom stone-faced terraces meant so much in the way of life-giving food should have sometimes built massive terraces of Cyclopean character, like Sacsahuaman, as an offering to the deity who first taught them terrace construction? This seems to me a more