  The Inca citadel of Machu Picchu is usually interpreted as a "royal estate"
of the Inca ruler Pachacuti. This idea is challenged here by a critical
reappraisal of existing sources and a re-analysis of existing evidences. It is
shown that such evidences actually point at a quite different interpretation.
This interpretation is suggested, on one side, by several clues coming from the
urban layout, the interior arrangement of the town, the ancient access ways,
the position with respect to the landscape and the cycles of the celestial
bodies in Inca times and, on the other side, by a comparison with known
information about the Inca pilgrimage center on the Island of the Sun of the
Titicaca lake. Altogether, the abovementioned clues lead to propose that Machu
Picchu was intentionally planned and built as a pilgrimage center connected
with the Inca "cosmovision".
