Slavery in Ghana
Under the battlements ringing Cape Coast Castle, Britain's former colonial seat in Ghana, a guide showed two dozen schoolgirls the underground passage linking the slave dungeons to the Door of No Return.
Until Britain led the world in outlawing the transatlantic slave trade 200 years ago next month, countless Africans shuffled through here to cramped ships waiting beyond the pounding surf.
But hundreds of Ghanaian girls the same age as those on their school trip to Cape Coast still live in conditions echoing the 18th century plantations in the Americas.
An ancient practice still strong in the country's north and east allows mystic priests to demand virgin brides as servants as atonement from families deemed to have offended ancestral gods.
Wrenched from their parents, the girls are kept captive in the priest's shrine and, even as children, are forced to work in his fields and clean his compound. When they reach puberty, they become his trokosi, or wife. Most are raped or sexually abused, many are beaten, campaigners have discovered.
"I was no better than an animal, working all day for the priest and I got nothing," said Enyonam Tordzro, 36, who spent 15 years as a trokosi after her grandfather had an affair with a neighbour's wife.
"I was sent there to pay for my grandfather's crime because people in the family were dying for no reason. If I ran away, I feared more people would die."
A campaign by local human rights organisations forced a change in Ghanaian law in 1998, prompting the liberation of 3,500 women and girls from the trokosi system, including Mrs Tordzro.
She now runs a village hairdressing business. "Now people respect me, that is the freedom I feel," she said. But 1,000 more trokosi are still enslaved and fear among lawyers and the police means that the law is rarely enforced. To date no one has been prosecuted.
"People might not be in chains but there's a very close semblance with the old style of slavery," said Rev Walter Pimpong, the director of International Needs Ghana, which led efforts to outlaw trokosi.
"Before, you had men with guns rounding up people who couldn't defend themselves. Now it's the priests who use their spiritual authority and power."
Close to Mrs Tordzro's village, 80 miles east of the capital Accra, her former master, Torgbi Mama Venanua, sat under a neem tree spilling schnapps on the ground as an offering to the gods. Mr Venanua, a smiling man in a white cotton robe and a woven reed mitre, was among the first trokosi priests to agree to give up his wives. "At first we didn't understand why we should change our traditions," he said, surrounded by village elders.
"But we consulted the deities and it became clear we could find other ways to compensate for the crimes. People can give us money or cows, we do not need wives any more."
Those who have yet to be set free are among the 12 million people who Anti-Slavery International estimate still suffer forms of enslavement.
These include boys forced to be camel jockeys in Gulf states; West African girls used as domestics; men forced to clear Amazon rainforest; and women trafficked to Western Europe.
“Wives of the Gods,” Slaves of Men
An ancient cult is alive and well in Ghana, taking girls as young as two and offering them as wives to appease their deities