[7] Before the Spanish conquest, Huaycán de Pariachi was one of the main administrative centers of the middle Rímac Valley.

[13][8][6] Sector 1 is the largest and consists of the remains of an ancient population or llaqta (Pariacha, according to the Huarochirí Manuscript).

It includes numerous spaces such as courtyards, open areas with benches, ramps, niches (not to be confused with niches carved into some walls, as some of them were used for funerary purposes during the colonial and republican eras), as well as numerous collqas[14][1][5] (deep circular storage deposits, some shaped like a bottle) used for storing food.

It connected Pariacha with other administrative centers in the valley, such as San Juan de Pariachi, Huanchihuaylas (now Santa Clara), Mama (now Ricardo Palma), and, through the Molle ravine pass, with Huaycán de Cieneguilla and the main Qhapaq Ñan road from Hatun Xauxa to Pachacamac in the Lurín Valley.

It covers an area of 18 hectares within a perimeter of 553 m, adjacent to the Horacio Zevallos Housing Development.