Chavín de Huantar was the place of origin of the second large-scale political entity in the central Andes, and this is mainly due to the extensive architecture at the site as well as the architecture is considered an engineering accomplishment. The site uses both internal and external architecture. Internal architecture refers to galleries, passageways, rooms, staircases, ventilation shafts, and drainage canals. External architecture refers to plazas, platform mounds, and terraces. Construction of the "Old Temple" took place from around 900 to 500 BCE, and construction of the "New Temple", the structure that was constructed and added on to the "Old Temple", took place from around 500 to 200 BCE. The lack of residential structures, occupational deposits, generalized weaponry, and evidence of storage further make the site's architecture more interesting, as it focuses mainly on the temples and what lies inside of them.