GOREE ISLAND, Senegal - Standing in a narrow doorway opening onto the Atlantic Ocean, tour guide Aladji Ndiaye asked a visitor to this Senegalese island's Slave House to imagine the millions of shackled Africans who stepped through it, forced onto overcrowded ships that would carry them to lives of slavery in the Americas.
"After walking through the door, it was bye-bye, Africa," said Ndiaye, pausing before solemnly pointing to the choppy waters below. "Many would try to escape. Those who did died. It was better we give ourselves to the sharks than be slaves."
This portal - called the "door of no return" - is one of the most powerful symbols of the Atlantic slave trade, serving as a backdrop for high-profile visits to Africa by Pope John Paul II, President Bill Clinton and President George W. Bush and a destination for thousands of African-Americans in search of their roots.
More than 200,000 people travel to this rocky island off the coast of Dakar each year to step inside the dark, dungeon-like holding rooms in the pink stucco Slave House and hear details of how 20 million slaves were chained and fattened for export here. Many visitors are moved to tears.
But whatever its emotional or spiritual power, Goree Island's real role in the slave trade remains a matter of dispute, a contest between history and the power of myth.
Despite the claims by Senegal's tour guides and tourism industry, Goree Island was never a major shipping point for slaves, say historians. No slaves were ever sold at what is known as the "House of Slaves." No Africans ever stepped through the famous "door of no return" to waiting ships, either.
"The whole story is phony," says Philip D. Curtin, a retired professor of history at the Johns Hopkins University who has written more than two dozen books on Atlantic slave trade and African history.
First used as stopover by Portuguese sailors in the 15th century, Goree Island was bought for a few iron nails by the Dutch before being seized by the French and the British.
Although it functioned as a commercial center, it was never a key departure point for slaves, Curtin says. Most Africans sold into slavery in the Senegal region would have departed from thriving slave depots at the mouths of the Senegal River to the north and the Gambia River to the south, he says.
During about 400 years of the Atlantic slave trade when an estimated 10 million Africans were taken from Africa, maybe 50,000 slaves - not 20 million as claimed by the Slave House curator - might have spent time on the island, Curtin says.
Even then, they would not have been locked in chains in the House of Slaves, Curtin says. Built in 1775-1778 by a wealthy merchant, it was one of the most beautiful homes on the island; it would not have been used as a warehouse for slaves other than those who might have been owned by the merchant.
Likewise, Curtin adds, the widely accepted story that the "door of no return" was the final departure point for millions of slaves is not true. There are too many rocks to allow boats to dock safely and a beach nearby that would have been the easiest place for loading ships, he says.
Curtin's assessment is widely shared by historians, including Abdoulaye Camara, curator of the Goree Island Historical Museum, which is a 10-minute walk from the Slave House.
The Slave House, says Camara, offers a distorted account of the island's history - created with tourists in mind.
No one is quite sure where the Slave House got its name, but both Camara and Curtin credit Boubacar Joseph Ndiaye, the Slave House's curator since the early 1960s, with promoting it as a tourist attraction.
Ndiaye is famous in Senegal for offering thousands of visitors chilling details of the squalid conditions of the slaves' holding cells, the chains used to shackle them and their final walk through the door of no return.
"Joseph Ndiaye offers a strong, powerful, sentimental history. I am a historian. I am not allowed to be sentimental," says Camara.
That said, Camara believes Ndiaye has played an important role in offering the descendents of slaves an emotional shrine to commemorate the sacrifices of their ancestors.
"The slaves did not pour through that door. The door is a symbol. The history and memory needs to have a strong symbol," Camara says. "You either accept it or you don't accept it. It's difficult to interpret a symbol."
Still, when historians have questioned the significance of the island and the Slave House, they have been met with accusations of revisionism.
The respected French newspaper Le Monde published an article in 1996 refuting the island's role in the slave trade; Senegalese authorities were furious. Several years ago at an academic conference in Senegal, some Senegalese accused Curtin of "stealing their history," Curtin said.
Despite widespread doubts of Goree Island's role in the slave trade, the United Nations Educational Scientific and Cultural Organization, which in 1978 designated the island a World Heritage site, actively promotes the Slave House as an important historical location.
"We are certain that the House of Slaves had something to do with the slave trade," says Edmond Moukala, a spokesman for UNESCO in Paris.
Some tour books, however, have begun warning visitors about the questions surrounding the island, including Lonely Planet's West Africa guide book, which concludes: "Goree's fabricated history boils down to an emotional manipulation by government officials and tour companies of people who come here as part of a genuine search for cultural roots."
None of the controversy appears to have diminished the island's attraction as a tourist destination. The ferry that carries visitors from Dakar to the island is regularly packed with tourists and school groups.
The island is a remarkable peaceful community with narrow streets, colonial homes, baobab trees and not one car in sight. Many of the island's 1,200 residents have come to depend on tourism, hawking African paintings, sculptures and necklaces, giving tours to visitors and running small seaside restaurants and hotels.
At the House of Slaves, the visitors' book is crowded with entries by tourists expressing a powerful mix of anger, sadness and hope at what they've experienced - no matter if it is fact or fiction.
"The black Africans will never forget this shameful act until kingdom come," penned a visitor from Ghana.
"My heart is sad," wrote a Canadian tourist, "This is the place I feel my ancestor's pain. But we are a beautiful, resilient people and we will stand."