Salvador was the first colonial capital of Brazil and its central district, Pelourinho, now a UNESCO world heritage site, was the New World's first slave market from 1553, according to UNESCO.

CNN: From Samba to carnival: Brazil's thriving African culture

About 240km west of Rio, the well-preserved Portuguese colonial town of Paraty is a slice of old Brazil by the sea.

BBC: Easy breaks from Rio de Janeiro

Argentina's northern province of Misiones, named for the settlements established during Spanish colonial times by the Catholic Church's Jesuit order, juts like a finger far into Brazil and Paraguay.

WSJ: Bird Watching in Misiones Province, Argentina