Unearthing Brazil's hidden slavery past

Major development work is under way in the Rio de Janeiro's historic port area as it prepares to host the Olympics in 2016.

But the construction effort has served up a reminder of the city's past as the largest entry point for African slaves in the Americas.

In 2011, excavation work uncovered the site of Valongo Wharf, where almost a million African slaves disembarked before the slave trade was declared illegal in Brazil in the 19th Century.

Among the artefacts already discovered are many objects of African origin such as ornaments, pipes and religious artefacts, as well as pieces of china, silverware, wooden dice and toothbrushes.

Julia Carneiro visited an old coffee warehouse in Rio where visitors will be able to observe archaeologists at work, sorting through the mounds of earth excavated from the construction sites.