RIO DE JANEIRO - Twisting their way through labyrinthine alleys, postmen in the Rio favela of Rocinha have to resort to detective work as they figure out where to deliver mail.
Police and the army moved in to clean up the sprawling mini-city of some 150,000 two years ago in a bid to rid Brazil's biggest slum of the scourge of drug dealers.
But even after "pacification" of the area, doing the rounds here can still be risky business.
"There's one house with a dog called warrior," said postal official Edson Martins.
Mailmen, no matter where, have long had to deal with vicious dogs. But their routes here are also rendered dangerous by Rocinha's maze of narrow streets and steep cliffside drops.
And then there's the fact that, as the area develops, some ramshackle abodes vanish and new ones spring up.
Just finding an address often requires a real sleuth.
"Sometimes, to get to a resident you have to go through the kitchen of another house," Martins told AFP.
Shanty houses dot the Rio hillside, with the structures providing shelter to tens of thousands - many work-hungry migrants from Brazil's poverty-stricken northeast.
Rocinha was a lawless bastion of drug dealers for some 30 years until troops and police, backed by helicopters and armored vehicles, moved in two years ago.
Since then, authorities have attempted to modernize the area and draw up a registry of streets, number houses and generally make some sense of a maze of paths and a jumble of electrical wires.
The postal service, for one, is tasked with attributing a zip code to each region to enable residents to get their mail at home.
"Before, road number four was just a simple pathway; today it's a real road, wider. That makes our job easier," says mailman Ricardo Pinto, 52.