At slavery-era sites in Rio, app unearths an uneasy history

For years, many Brazilians have argued that the country's story of slavery is buried out of sight – literally, in Rio de Janeiro, once home to the Americas' biggest slave port. The Museum of Yesterday, an augmented reality app, tries to put that history in users' hands.

Renata Brito/AP

Just as rush hour begins in Rio de Janeiro’s Port Zone, bordering the city’s bustling downtown, Gabriele Roza looks kitty-corner across a busy street. Between buses and taxis rushing through the intersection, she points to a small plaza: half a dozen buildings fan out, all tagged with graffiti and some with broken windows. They’re a reminder of the city’s uncomfortable history – although there’s no way to tell at first glance.