Cape Coast Castle is one of around forty ‘slave castles’ built by European traders on the coast of West Africa and used to hold enslaved Africans prior to their being transported to the Americas or the Caribbean. The first timber construction on the site was erected in 1653 for the Swedish Africa Company named Carolusborg. It was later rebuilt in stone. In April 1663 the ‘Swedish Gold Coast’ was seized by the Danes and integrated into the ‘Danish Gold Coast’. In 1664 it was conquered by the British. Originally used for trade in timber and gold, the castle was later used in the transatlantic slave trade. In the late 18th century it was rebuilt and used as the seat of the colonial Government of the British Gold Coast in 1844. In 1957, when Ghana became independent, the site came under the care of the Ghana Museums and Monuments Board, and was restored for public access in the 1990s. The museum offers guided tours, as well as permitting tours orchestrated by freelance tour guides. There is also a library and a gift shop, featuring traditional Ghanaian arts and crafts, on site.

The main aim of the museum is to act as a monument to those taken from Africa and enslaved into the system of Transatlantic Slavery. It features both archaeological and ethnographic collections on displays, within the rooms of the castle. Throughout, there are also a number of contemporary sculptures depicting the heads of victims of the slave trade. Visitors tour through the castle, encountering the rooms in which the enslaved were held, with guides providing further information about the conditions and experiences those thousands of Africans faced.

The museum is housed within Ussher Fort, one of three European forts built in the Accra region of Ghana during the mid-seventeenth century. Developed by Ghana's Ministry of Tourism, with support and funding from UNESCO, the museum opened in 2007.

The museum aims to highlight the history of the transatlantic slave trade in Ghana. Beginning with the development of the trade in human beings, the museum covers the history through to British abolition.

The collection is varied and includes items once used by both captors and victims. There are weapons, African household items and a model of a slave vessel. The museum also contains paintings of several key abolition figures, including William Wilberforce and Harriet Tubman.