Brazil is almost an undiscovered country for the international bicycle-travel community. Long-haul South American routes go down the west side of the continent. Historically this was blamed on Brazil's roads being regarded as unusually narrow and dangerous. However, in the bikepacking era when lots of people want to ride rough tracks, not roads with many vehicles, it's odd that no such rough routes across Brazil have become popular among cyclists coming to the region from elsewhere.
The western routes offer favourable climate conditions for cycling. Brazil's savannah is alright but the idea of pedalling 1000s of kilometres through the heat, humidity and mosquitoes of the amazon sounds atrocious to me.
I've driven along the coastline of Uruguay. Always wanted to return for a bikepacking trip. Beautiful landscape.