  Summer 2015 marked the 100th anniversary of the excavation by J.W. Fewkes of
the Sun Temple in Mesa Verde National Park, Colorado; an ancient ceremonial
complex of unknown purpose, prominently located atop a mesa, constructed by the
Pueblo Indians approximately 1000 years ago. In this analysis we perform a
digital survey of the site, and examine the possibility that four key
tower-like elements of the complex were used for observation of the rise or set
of celestial bodies known to be sacred to the Pueblo Indians.
  We find statistically significant evidence that the site was used for
astronomical observation of the rise and/or set of nearly all such bodies. The
Sun Temple appears to represent the most comprehensive prehistoric astronomical
observatory yet uncovered.

History and Philosophy of Physics;Popular Physics