Parauapebas is a city in Pará. This is true frontier country: There was virtually nothing in this region until the world's largest iron ore mine, at neighbouring Serra dos Carajás was set into production in the early 80ies. The city still has an air of pioneers and adventurers.
Marabá, some 200 km off is the regional bus hub, for transport onwards to Belém(about 12 hours), Imperatriz(about 10 hours) or Brasília. Road travel times may increase significantly during rainy season.
There is a train all the way to São Luís thrice a week , along the railway that exports the ore of the region. 16 hours ride!