| Argentina | Southern cone; Andes west, Atlantic east. | Southern Cone |
| Bolivia | Landlocked; Altiplano + Amazon lowlands. | Central Andes |
| Brazil | Largest state; Amazon Basin dominates. | Eastern / Amazon / Southern Cone border |
| Chile | Narrow Pacific strip; Andes wall. | Southern Cone (Pacific) |
| Colombia | Northern gateway; triple-split Andes. | Northern Andes / Caribbean |
| Ecuador | Andean spine; coastal lowlands; Amazon. | Northern Andes |
| French Guiana | Atlantic-facing; dense Amazonian interior; ESA launch site. | Guianas |
| Guyana | Caribbean-facing; Guiana Highlands. | Guianas (Caribbean) |
| Paraguay | Landlocked; forested east + Chaco. | Central Lowlands |
| Peru | Andes, coastal desert, Amazon interior. | Central Andes |
| Suriname | Atlantic-facing; tropical rainforest. | Guianas |
| Uruguay | Rolling plains; buffer between giants. | Southern Cone |
| Venezuela | Caribbean coast; Llanos; Orinoco Basin. | Northern South America |
