Luckily there are no more slaves, but Ouidah has been the centre of the "slaves route" where many people retrace the steps of the days when the ships stopped in the dock and picked up labourers to meet their every need. This often involved the slaves travelling to the other side of the world to cater to every whim of their owner, never to be seen by their family again.
Seek shelter under the Tree of Forgetfulness, step through the Gate of No Return and explore other memorials that were part of slaves' rituals before they left Benin. Many museums represent Dahomey, a prominent West African kingdom that rose in the 15th century that specialised in slave trade and Benin was rescued when it became a French Colony in 1872. If a day trip is too little, various tour companies offer packages of 5-16 day tours. Their trip includes overnight visits to Ouidah to visit the Sacred Forest, the History Museum of Ouidah, and the Python Temple.
There is much history to explore as the slave trade in Africa existed for thousands of years. The first main route passed through the Sahara but soon African slaves became part of the Atlantic slave trade. Despite its illegality, there are rumours that slavery continues in some parts of the world, but after this tour you will hope this to be untrue. Slavery often involved violence, cruelty, abuse and inhumane acts that should be abolished and a trip to Benin will convince any traveller that slavery is a sin.