ne,
and bronze, had crumbled away before the attacks of savage hordes
who knew little of the arts of peace. The defeated leaders had to
choose a region where they might live in safety from their fierce
enemies. Furthermore, in the environs of Machu Picchu they found
every variety of climate--valleys so low as to produce the precious
coca, yucca, and plantain, the fruits and vegetables of the tropics;
slopes high enough to be suitable for many varieties of maize,
quinoa, and other cereals, as well as their favorite root crops,
including both sweet and white potatoes, oca, anu, and ullucu. Here,
within a few hours' journey, they could find days warm enough to dry
and cure the coca leaves; nights cold enough to freeze potatoes in
the approved aboriginal fashion.

Although the amount of arable land which could be made available with
the most careful terracing was not large enough to support a very
great population, Machu Picchu offered an impregnable citadel to the
chiefs and priests and their handful of followers who were obliged
to flee from the rich plains near Cuzco and the broad, pleasant
valley of Yucay. Only dire necessity and terror could have forced a
people which had reached such a stage in engineering, architecture,
and agriculture, to leave hospitable valleys and tablelands for rugged
canyons. Certainly there is no part of the Andes less fitted by nature
to meet the requirements of an agricultural folk, unless their chief
need was a safe refuge and retreat.

Here the wise remnant of the Amautas ultimately developed great
ability. In the face of tremendous natural obstacles they utilized
their ancient craft to wrest a living from the soil. Hemmed in
between the savages of the Amazon jungles below and their enemies
on the plateau above, they must have carried on border warfare for
generations. Aided by the temperate climate in which they lived,
and the ability to secure a wide variety of food within a few hours'
climb up or down from their towns and cities, they became a hardy,
vigorous tribe which in the course of time burst its boundaries, fought
its way back to the rich Cuzco Valley, overthrew the descendants
of the ancient invaders and established, with Cuzco as a capital,
the Empire of the Incas.

After the first Inca, Manco Ccapac, had established himself in Cuzco,
what more natural than that he should have built a fine temple in
honor of his ancestors. Ancestor worship was common to the Incas,
and noth