Andes
The Andes or Andean Mountains () are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. This range is about long, about wide (widest between 18° south and 20° south latitude), and of an average height of about . The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina.
Crossing of the Andes
The idea of crossing the Andes was already developed by secret lodges seeking the independence of South America, and was part of the Maitland Plan designed by Thomas Maitland. San Martín learned of it during his brief time in Britain, before sailing to South America. After becoming aware of the difficulty of attacking the royalist stronghold of Lima across Upper Peru, he decided to proceed with such a plan.