According to the scholar Kim
MacQuarrie, Pachacuti erected a number of royal estates to memorialize
victories over other ethnic groups. Among these royal estates are Písac
(victory over the Cuyos), Ollantaytambo (victory over the Tambos), and Machu
Picchu (conquest of the Vilcabamba Valley). Other historians suggest that Písac
was established to protect Cusco from possible attacks of the Antis nations. It
is unknown when Inca Písac was built. Since it does not appear to have been
inhabited by any pre-Inca civilization, it was most likely built no earlier
than 1440.
