In 1894, when the Belgian city of Antwerp was hosting a World's Fair, more than a hundred Congolese people were forcibly brought to the city to be exhibited in the Congo Pavilion. In this "human zoo", seven Congolese men ultimately died of disease. Today, this shocking episode still haunts Belgium as one of its colonial history's darkest chapters. This year, a monument to the victims was unveiled. Report by Alix le Bourbon and Dave Keating.