In ancient times, on the current Mantaro or Jauja valley, which was covered by the waters of a great big lake in which center stands a rock called Wanka, a place of rest for Amaru, a horrible monster with the head of a llama, two tiny wings and the body of a batrachian that ended with a snake tail. Later on, the tulunmaya (rainbow) spawned another Amaru, partner of the first and of a darker color; the latter never reached the size of the first that because of its age have become white.
Both monsters fought over the dominance of the lake, and even though the rock was of great dimension it was not big enough to house both of them at the same time. On these continuous struggles, so violent that they would rise up great lengths in the space over waterspouts, shaking the lake, the big Amaru lost a great chunk of its tails when furiously attacking the smaller one.
Irritated, the Tikse god unleashed upon them a great storm and its thunders killed both of them who fell destroyed with heavy rain over the already shaken up lae, engorging its volume until breaking its shores and emptying down south.
When the valley was formed, from the Warina o Wari-puquio (wari means unprofaned shelter that keeps something or someone sacred, and puquio means water spring) came out the first two human beings, called Mama and Taita that until then had been hidden under earth in fear of the Amarus.
The descendants of this couple later butyl the Warwillka temple and its ruins can still be found nowadays.
Source: Peruvian Myths, Legends and Stories (Jose Maria Arguedas)
View More: http://www.trip-peru.com/tour.php?tour=99