Some 2,500 years ago, a mysterious culture emerged in Nigeria. The Nok people left behind bizarre terracotta statues - and little else. Archaeologists are now looking for more clues to explain this obscure culture...

...Like their cemeteries, the temples and huts of the Nok have disappeared without a trace. No one knows what their farm animals, streets or religious ceremonies were like. But the shards of clay statues are everywhere - on rock slopes, in ancient refuse pits and in open spaces. The largest of these impressive figures can stand up to one meter (3.3 feet) tall and resemble what might be kings or members of a social elite. Others wear horned helmets or carved-out gourds on their heads. A third of these figures are women...

... For the time being, though, the purpose of the Nok statues remains unclear. And then there's still the question of whether these objects have anything to do with the Nok people making contact with other people. "There's no doubt that the Nok will continue to baffle us," Breunig says. "We're unearthing a magnificent part of the history of sub-Saharan Africa."