Bolas are arguably the fundamental technology that allowed Native peoples to live in the Pampas and northern Patagonia for millennia. This hunting weapon—made up of several cords weighted with stones at one end and knotted together at the other—was used for centuries by Tehuelche, Lengua, and other groups to ensnare animals. Each weight was covered in fresh leather that would shrink as it dried to hold the stone snugly.