Eastern Pacific High Sea

Facing this broad section of the eastern Pacific, the Andean region forms the long western backbone of South America. The mountain system extends about 7,000 kilometres along the continent in one account of its geography, with widths varying from 200 to 700 kilometres. Its parallel cordilleras, high plateaus and deep valleys create steep gradients between humid cloud forest, dry high plains and glaciated summits. This terrain has shaped both settlement and movement, concentrating cities on high plateaus and leaving some mountain communities dependent on footpaths, pack animals and difficult crossings.

The Andes are equally important for the history of the lands behind the Pacific coast. Irrigation has been practiced there for more than 6,000 years, and terracing became extensive after Inca expansion. Potatoes were a staple, while maize was used to make chicha; llamas and alpacas served as pack animals and provided meat and wool. A long sequence of cultures culminated in the Inca Empire during the fifteenth century. Its roads and aqueducts drew on earlier work and linked a state that had expanded through conquest and detailed administration.

After the Inca defeat in 1532, Spanish rule turned Andean mineral wealth into a large mining economy. Potosí and Cerro de Pasco became major centers, and commodities such as silver, tin and copper tied the mountains to Atlantic and Pacific commerce. The range therefore connects a vast ocean horizon to dense highland societies, route networks and movement corridors.